Valgus stress radiography following superficial medial collateral ligament reconstruction using a modified LaPrade technique with adjustable loop femoral fixation.

Purpose of this study was to assess postoperative laxity of MCL reconstructions utilizing a modified LaPrade superficial MCL reconstruction. We retrospectively reviewed post-operative valgus stress radiographs in 23 multiligament injured patients who underwent concurrent sMCL and cruciate ligament reconstruction by a single surgeon. Post- operatively, 23 patients underwent valgus stress radiographs that were assessed at a mean of 8.7 months (range: 4-13 months), and mean SSD was 0.64mm ± 0.42mm. Eight patients underwent both pre- and post-operative valgus stress radiographs. Post-operative (0.09mm ± 0.63mm) SSD was found to be significantly reduced compared to pre-operative (2.07mm ± 0.44mm) SSD (mean diff. = 1.98mm, 95% CI = 0.72-3.24, P=0.007). Inter-observer reliability value for medial compartment gap measurement was 0.91 with a 95% confidence interval of 0.34- 0.97. In conclusion, presented technique results in excellent static stability of the knee as measured by valgus stress radiography at a minimum of 6 months postoperative. Level of Evidence: IV.

The use of a prosthetic inlay resurfacing as a salvage procedure for a failed cartilage repair.

PURPOSE: This study was designed to describe the clinical and radiographical outcome of the HemiCAP(®) resurfacing system as a salvage treatment for a failed index cartilage procedure. METHODS: Fourteen patients were treated consecutively and clinically prospectively followed for a mean period of 26.1 ± 12.8 months. All patients were previously treated for their cartilage lesion. Radiographical data were analysed based on the Kellgren and Lawrence system. RESULTS: The patients involved in this study demonstrated a gradual clinical improvement in time. However, radiographically significant osteoarthritic changes were observed during the follow-up period. The position of the HemiCAP(®) resurfacing system was adequate in all cases, and no signs of loosening were observed during the follow-up period. CONCLUSIONS: The HemiCAP(®) resurfacing system is feasible as a salvage treatment for a failed index cartilage procedure and resulted in a gradual clinical improvement. However, the favourable clinical outcome was not confirmed by the radiographical findings. LEVEL OF EVIDENCE: IV.

Clinical and MRI outcome of an osteochondral scaffold plug for the treatment of cartilage lesions in the knee.

Conflicting clinical outcomes have been reported recently with the use of an osteochondral scaffold plugs for cartilage repair in the knee. In this study, twenty patients were consecutively treated for their cartilage lesions with the synthetic plug technique. These patients were prospectively clinically evaluated with a mean follow-up of 34.15 months. Magnetic resonance imaging (MRI) was used for morphologic analysis of the cartilage repair. The patients included in this study showed a significant gradual clinical improvement after the osteochondral scaffold plug. However, this clinical improvement was not confirmed by the MRI findings of this cohort study. Subchondral bone changes were seen in all patients on MRI and deficient filling of the defect was noticed in in 30.7% of the cases at 24 months of follow-up. There was no evidence found to support osteoconductive bone ingrowth. Therefore, the use of this type of osteochondral scaffold plug in osteochondral repair is questionable. Level of evidence: IV.

Constitutional varus does not affect joint line orientation in the coronal plane.

BACKGROUND: In a previous study, we described the distribution of coronal alignment in a normal asymptomatic population and recognized the occurrence of constitutional varus in one of four individuals. It is important to further investigate the influence of this condition on the joint line orientation and how the latter is affected by the onset and progression of arthritis. QUESTIONS/PURPOSES: The purposes of this study are (1) to describe the distribution of joint line orientation in the coronal plane in the normal population; (2) to compare joint line orientation between patients with constitutional varus and neutral mechanical alignment; and (3) to compare joint line orientation between a cohort of patients with prearthritic constitutional varus and a cohort of patients with established symptomatic varus arthritis. METHODS: Full-leg standing hip-to-ankle digital radiographs were performed in 248 young healthy individuals and 532 patients with knee arthritis. Hip-knee-ankle (HKA) angle and tibial joint line angle (TJLA) were measured in the coronal plane. Patients were subdivided into varus (HKA ≤ -3°), neutral, and valgus (HKA ≥ 3°). RESULTS: The mean TJLA in healthy subjects was 0.3° (SD 2.0°). TJLA was parallel to the floor in healthy subgroups with neutral alignment (TJLA 0.3°, SD 1.9) and constitutional varus (TJLA 0.2°, SD 2.2°). In patients with symptomatic arthritis and varus alignment, the TJLA opened medially (mean -1.9°, SD 3.5°). CONCLUSIONS: Constitutional varus does not affect joint line orientation. Advanced medial arthritis causes divergence of the joint line from parallel to the floor. These findings influence decision-making for osteotomy and alignment in total knee arthroplasty.

Treatment of patellofemoral cartilage defects in the knee by autologous matrix-induced chondrogenesis (AMIC.

This study presents the prospective two-year clinical and MRI outcome of autologous matrix-induced chondrogenesis (AMIC) for the treatment of patellofemoral cartilage defects in the knee. Ten patients were clinically prospectively evaluated during 2 years. MRI data were analysed based on the original and modified MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) scoring system. A satisfying clinical improvement became apparent during the 24 months of follow-up. The MOCART scoring system revealed a slight tendency to deterioration on MRI between one and 2 years of follow-up. However, the difference was not statistical significant. All cases showed subchondral lamina changes. The formation of intralesional osteophytes was observed in 3 of the 10 patients (30%). In conclusion, AMIC is safe and feasible for the treatment of symptomatic patellofemoral cartilage defects and resulted in a clinical improvement. However, the favourable clinical outcome of the AMIC technique was not confirmed by the MRI findings.

Patellar tilt and thickness do not influence postoperative flexion in a high-flex design total knee arthroplasty.

PURPOSE: The purpose of this short-term study was to determine whether patellar thickness and tilt influence the postoperative flexion in a high-flex design total knee arthroplasty (TKA). METHODS: Between 2007 and 2009, 106 patients underwent surgery for TKA using rotating platform flex prosthesis (DePuy, Warsaw, Ind). All of them were suffering from end-stage osteoarthritis. All patients were evaluated preoperatively and at 12 months of follow-up. Maximum active, non-weight-bearing flexion was the primary outcome parameter. Standard standing antero-posterior and lateral weight-bearing radiographs were made. The patellofemoral joints were evaluated in skyline views taken with the knees at approximately 60° of flexion. Patellar thickness, patellar tilt, Caton-Deschamps indices and lower limb alignment were measured. RESULTS: The mean flexion observed before surgery was 125° ± 15° and after 1 year was 128° ± 13°. The mean patellar thickness preoperatively was 24.5 ± 2.9 and 25.8 ± 3.2 mm at 12 months after surgery. The mean patellar tilt before the procedure was 2.9° ± 4.1° and after 12 months of follow-up was -0.8° ± 5.0°. The mean preoperative hip-knee-ankle was 2.6° ± 6.2°. No significant correlation was found between postoperative patellar tilt and thickness and postoperative flexion (n.s.). CONCLUSIONS: Patellar tilt and thickness after TKA are factors that depend on the surgery. The resection of the patella can influence both patellar thickness and patellar tilt. By developing adequate surgical instruments, it would be possible to avoid the occurrence of an exaggerated patellar tilt or a major difference in patellar thickness. However, these two factors did not seem to influence the postoperative flexion in a high-flex design TKA, which can be seen as one of the most important outcome factors after TKA.

Histologic assessment of acetabular labrum healing.

PURPOSE: The purpose of this study was to histologically examine the human healing response of arthroscopically repaired acetabular labrum tears. METHODS: Biopsy specimens were retrieved from 6 patients during total hip arthroplasty after clinical failure of the index arthroscopic procedure. All patients were diagnosed as having femoroacetabular impingement with a concomitant labral tear. In all cases severe chondral damage was observed during arthroscopy (Beck grades 3 to 4). Despite successful technical repair of the labral tear, chondral damage in these patients was so advanced that the clinical progress after the procedure was unsatisfactory and arthroplasty of the joint was required. Biopsy specimens of the repaired acetabular labra were harvested during the arthroplasty surgery and processed for standard histologic evaluation. RESULTS: Macroscopically and histologically, all repaired labra kept their triangular shape more or less and appeared to have healed. All harvested biopsy specimens displayed a typical fibrocartilaginous appearance with limited vascular supply. Calcifications were present in only 1 biopsy specimen. In 3 cases neovascularization of the labral tissue was noticed in the proximity of the sutures. In the superficial and deep parts of the labral body, small clefts were observed in all cases. CONCLUSIONS: In this study the histologic aspects of arthroscopically repaired human labral tears were addressed. It was shown that human labral tears show healing potential after surgical repair. The surfaces of the labral tissues were intact, and neither remnants of the tear nor the presence of fibrovascular scar tissue was observed. However, some small clefts in the superior and deep parts of the repaired structures were noticed in all cases. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

A pilot study of the use of an osteochondral scaffold plug for cartilage repair in the knee and how to deal with early clinical failures.

PURPOSE: To present our short-term experience with an osteochondral scaffold plug (TruFit plug; Smith & Nephew, Andover, MA) for cartilage repair in the knee and, more importantly, to discuss our approach to treat early clinical failures. METHODS: Twenty patients were consecutively treated for their cartilage lesions with the plug technique. These patients were prospectively clinically evaluated at 6 and 12 months of follow-up. Magnetic resonance imaging (MRI) was used for morphologic analysis of the cartilage repair. Biopsy samples were taken from 3 cases during revision surgery, allowing histologic assessment of the repair tissue. RESULTS: The short-term clinical and MRI outcome of this pilot study are modest. No signs of deterioration of the repair tissue were observed. Of the 15 patients followed up during 1 year, 3 (20.0%) showed persistent clinical symptoms or even more clinical symptoms after insertion of the plug. These patients were considered as failures and therefore eligible for revision surgery. During revision surgery, the repair tissue was carefully removed. The remaining osteochondral defect was filled with autologous bone grafts. Immediate and persistent relief of symptoms was observed in all 3 patients. Histologic assessment of biopsy specimens taken during revision surgery showed fibrous vascularized repair tissue with the presence of foreign-body giant cells. CONCLUSIONS: The overall short-term clinical and MRI outcome of the osteochondral scaffold plug for cartilage repair in the knee is modest. In this pilot study a modest clinical improvement became apparent at 12 months of follow-up. MRI data showed no deterioration of the repair tissue. Of the 15 patients, 3 (20%) had persistent clinical symptoms after surgery. These patients were successfully treated with removal of the osteochondral plug remnants and the application of autologous bone grafts. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

The use of scaffolds in the treatment of osteochondral lesions in the knee: current concepts and future trends.

Long after the first reports on human autologous chondrocyte implantation (ACI) by Brittberg in 1994, the development of a so-called optimal technology for osteochondral tissue regeneration is still one of the most challenging issues in knee surgery. Although the short- and intermediate-term results of ACI appear to be favorable, resources are being directed toward scaffold research to improve the technology. Scaffolds used for osteochondral repair may be either cell or noncell-based before its implantation in the knee. The characteristics that make scaffolds optimal for clinical use are that they be biocompatible, biodegradable, permeable, reproducible, mechanically stable, noncytotoxic, and capable of serving as a temporary support for the cells while allowing for eventual replacement by matrix components synthesized by the implanted cells. There is a growing interest in noncell and last-minute cell seeding technologies since they allow for a one-step surgery eliminating the morbidity and necessity of a previous chondral biopsy. Although clinical and histological results from many, already clinically available scaffolds seem to be promising, improvements throughout these technologies and the developments of new ones are still necessary to obtain a more efficient biological response as well as to improve the implant's stability. Moreover, as the understanding of interactions between articular cartilage and subchondral bone continues to evolve, increased attention should be directed at treatment options for the entire osteochondral unit, rather than focusing on the articular surface only.

Optimized alkylated cyclodextrin polysulphates with reduced risks on thromboembolic accidents improve osteoarthritic chondrocyte metabolism.

OBJECTIVES: To compare the ability of different cyclodextrin polysulphate (CDPS) derivatives to affect human articular cartilage cell metabolism in vitro. METHODS: OA chondrocytes were cultured in alginate and exposed to 5 µg/ml of 2,3,6-tri-O-methyl-ß-cyclodextrin (ME-CD), 2,3-di-O-methyl-6-sulphate-ß-cyclodextrin (ME-CD-6-S), 2,6-di-O-methyl-3-sulphate-ß-cyclodextrin (ME-CD-3-S), (2-carboxyethyl)-ß-CDPS (CE-CDPS), (2-hydroxypropyl)-ß-CDPS (HP-CDPS), 6-monoamino-6-monodeoxy-ß-CDPS (MA-CDPS) or ß-CDPS for 5 days. Effects on IL-1-driven chondrocyte extracellular matrix (ECM) metabolism were assayed by analysis of the accumulation of aggrecan in the interterritorial matrix, IL-6 secretion and qPCR. MA-CDPS, HP-CDPS, CE-CDPS and CDPS were analysed for their in vitro effect on coagulation and their ability to activate platelets in an in vitro assay to detect possible cross-reactivity with heparin-induced thrombocytopenia (HIT) antibodies. RESULTS: The monosulphated cyclodextrins ME-CD-6-S and -3-S failed to affect aggrecan synthesis and IL-6 secretion by the OA chondrocytes. Polysulphated cyclodextrins MA-CDPS, HP-CDPS, CE-CDPS and CDPS at 5 µg/ml concentrations, on the other hand, significantly induced aggrecan production and repressed IL-6 release by the chondrocytes in culture. aPTT and PT for all derivatives were lengthened for polysaccharide concentrations >50 µg/ml. Five micrograms per millilitre of ß-CDPS concentrations that significantly modulated ECM ground substance production in vitro did not affect aPTT or PT. Furthermore, CE-CDPS, in contrast to MA-CDPS, HP-CDPS and CDPS, did not significantly activate platelets, suggesting a minimal potential to induce HIT thromboembolic accidents in vivo. CONCLUSIONS: CE-CDPS is a new, structurally adjusted, sulphated ß-cyclodextrin derivative with preserved chondroprotective capacity and a promising safety profile.

Twenty-six years of meniscal allograft transplantation: is it still experimental? A meta-analysis of 44 trials.

PURPOSE: since the first meniscal allograft transplantation in 1984, thousands of patients with postmeniscectomy symptoms have been treated by allograft replacement. This study aims the collection, presentation and meta-analysis of published trials reporting outcomes of meniscal allograft transplantation to establish its safety and reproducibility. METHODS: a literature search was conducted and the abstracts of all English-language trials with a more than 6 months' clinical, radiological and/or histological follow-up in human subjects were reviewed. Forty-four trials representing 1,136 grafts in 1,068 patients were analyzed. To assess the methodological quality of the collected data, original and modified Coleman methodology scores were determined for all included papers. RESULTS: the outcomes of 678 medial and 458 lateral grafts in 613 male, 265 female and 190 nondefined patients with a mean age of 34.8 years were presented. The outcome was assessed using 12 scoring systems, 4 imaging modalities, second-look arthroscopy and/or histological analysis. Whatever the follow-up period and the scoring system used, patients continuously showed clinical improvement. The average original Coleman scores were 45.9 ± 8.4 (range 25-59). The average modified Coleman scores were 43.7 ± 9.1 (range 24-62). CONCLUSIONS: all studies reported a continuously satisfactory outcome with restoration of working capacity in these active patients. The complication and failure rates are considered acceptable by all authors. Salvage procedures included osteotomy and arthroplasty without secondary difficulties. Meniscal allograft transplantation can be considered as safe and reliable for the treatment of refractory postmeniscectomy symptoms in selected patients. LEVEL OF EVIDENCE: IV.

Meniscus Scaffolds for Partial Meniscus Defects.

The meniscus is a crucial player in knee joint homeostasis. Loss of meniscus tissue can result in early onset of clinical symptoms like pain and loss of function, and structural degeneration of the articular cartilage. In case of a symptomatic segmental defect of the medial or lateral meniscus, different innovative options using biological or synthetic scaffolds are now available to regenerate meniscuslike tissue, with the aim of allowing a satisfactory clinical improvement to patients. However, the role of any of these procedures in terms of chondroprotection is questionable, and the overall outcomes in the long term still can be improved.

Polyurethane Meniscal Scaffold for the Treatment of Partial Meniscal Deficiency: 5-Year Follow-up Outcomes: A European Multicentric Study.

BACKGROUND: A biodegradable polyurethane scaffold was developed to treat patients with the challenging clinical condition of painful partial meniscal defects. HYPOTHESIS: The use of an acellular polyurethane scaffold in patients with symptomatic partial meniscal defects would result in both midterm pain relief and improved function. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 155 patients with symptomatic partial meniscal defects (101 medial and 54 lateral) were implanted with a polyurethane scaffold in a prospective, single-arm, multicentric study with a minimum 5-year follow-up. Clinical outcomes were measured with the visual analog scale for pain, International Knee Documentation Committee subjective knee evaluation form, Lysholm knee scale, and Knee injury and Osteoarthritis Outcome Score at baseline and at 2- and 5-year follow-ups. Magnetic resonance imaging (MRI) was used to evaluate the knee joint, meniscal implant, and meniscal extrusion. Kaplan-Meier survival analysis was also performed. Removal of the scaffold, conversion to a meniscal transplant, and unicompartmental/total knee arthroplasty were used as endpoints. RESULTS: Eighteen patients were lost to follow-up (11.6%). The patients who were included in this study showed significant clinical improvement after surgery as indicated by the different outcome measures (P = .01). However, the clinical improvement tended to stabilize between 2 and 5 years of follow-up. MRI scans of the scaffolds in 56 patients showed a smaller-sized implant in the majority of the cases when compared with the native meniscus with an irregular surface at the 5-year follow-up. During the follow-up period, 87.6% of the implants survived in this study. At 5 years of follow-up, 87.9% of the medial scaffolds were still functioning versus 86.9% of the lateral scaffolds. In total, 23 treatments had failed: 10 removed scaffolds because of breakage, 7 conversions to meniscal allograft transplantation, 4 conversions to unicompartmental knee arthroplasty, and 2 conversions to total knee arthroplasty. CONCLUSION: The polyurethane meniscal implant was able to improve knee joint function and reduce pain in patients with segmental meniscal deficiency over 5 years after implantation. The MRI appearance of this scaffold was different from the original meniscal tissue at the midterm follow-up. The treatment survival rates of 87.9% of the medial scaffolds and 86.9% of the lateral scaffolds in the present study compared favorably with those published concerning meniscal allograft transplantation after total meniscectomy.

Pharmacokinetic Profile of Intra-articular Fluticasone Propionate Microparticles in Beagle Dog Knees.

OBJECTIVE: The objective of this pilot study was to determine time point(s) at which maximum concentration of fluticasone propionate (Cmax) occurs in synovial fluid and plasma in Beagle dog knees after intra-articular injection of EP-104IAR. DESIGN: EP-104IAR is composed of fluticasone propionate drug crystals coated with heat-treated polyvinyl alcohol (PVA) to result in extended release properties. Thirty-two Beagle dogs had an injection of EP-104IAR into the knee joint at 2 different dose levels (0.6 mg and 12 mg). Outcome measures included plasma, synovial fluid, and articular cartilage fluticasone propionate concentrations as well as histological analysis of cartilage and synovium at a variety of time points up to 58 days postdosing. RESULTS: Intra-articular administration of 0.6 and 12 mg EP-104IAR was well tolerated. Early minor abnormalities found on microscopy resolved by the end of the study. There were no quantifiable concentrations of fluticasone propionate in plasma of animals administered 0.6 mg at any of the sampling time points. Highest concentrations in plasma following 12 mg administration occurred 1 day postdose and declined with a half-life of approximately 45 days. Highest concentrations of fluticasone propionate in synovial fluid and cartilage generally occurred 5 days postdose in both dose groups and declined with a half-life of approximately 11 to 14 days. CONCLUSIONS: EP-104IAR is capable of providing a safe and prolonged local exposure to a corticosteroid in the synovial joint while minimizing systemic exposure, with peak exposures occurring within a matter of days after dosing before declining in all tissues in a predictable manner.

Anterolateral Ligament Reconstruction or Extra-Articular Tenodesis: Why and When?

Residual rotational laxity following anterior cruciate ligament (ACL) reconstruction has been identified as significant concern in many patients, despite evolution of techniques. The expanding body of knowledge on the anatomy and biomechanics of the anterolateral soft tissue restraints in rotational control of the knee has reignited an interest in extra-articular reconstruction techniques for augmenting ACL reconstruction. Reconstruction techniques currently used can be broadly categorized as either lateral extra-articular tenodesis or reconstruction of the anterolateral ligament. In this article, we outline the relevant anatomy, biomechanics, and rationale behind the indications and technique of our current extra-articular augmentation procedure.

Determination of knee cartilage volume and surface area in beagle dogs: a pilot study.

BACKGROUND: The objective of this study was to determine the cartilage volume and surface area of male and female Beagle dog knees using 3D (3 dimensional) reconstructed MRI images. METHODS: Six Beagle Dogs (Canis familiaris) (3 males and 3 females) of 10-18 months old and weighing between 7.2 and 17.1 kg underwent a MRI evaluation of both knees. The data acquired allowed a 3D reconstruction of the knee and measurement of the cartilage volume and surface area. RESULTS: Mean knee cartilage volume (averaged over the right and left knees) of animals between 7.2 and 17.1 kg ranged from 319.7 to 647.3 mm3; while the mean knee cartilage surface area ranged from 427.14 to 757.2 mm2. There was evidence of both knee volume and surface area increasing linearly with animal bodyweight. CONCLUSIONS: The cartilage volume and surface area of the Beagle dog appears to correlate significantly with body weight. This study provides a reference base for future studies investigating cartilage related pathology such as osteoarthritis.

Three-dimensional analysis of accuracy of component positioning in total knee arthroplasty with patient specific and conventional instruments: A randomized controlled trial.

BACKGROUND: Component malalignment remains a major concern in total knee arthroplasty (TKA). Patient-specific guides (PSG) were developed to increase accuracy of bone resections and component placement, but available evidence is contradictory. We assessed the accuracy of 3D component placement in TKA with PSG compared to conventional surgery using virtual 3D bone models. METHODS: Fifty patients were randomly assigned to the PSG or conventional instrumentation group, 44 were finally analyzed. Preoperatively, MRI and CT scans were converted into virtual 3D models and a surgical plan was developed. Surgery was performed and changes in component sizing were recorded. Postoperative CT images were converted to 3D models and aligned to the planned, preoperative models and implant orientation. Differences between planned and postoperative implant orientations were calculated in 3D. RESULTS: PSG allowed significantly more accurate varus/valgus placement for the femoral component (PSG: 0.14±1.47; control: 1.40±1.99; p<0.05), but more slope was introduced (PSG: 2.82±2.42; control: 0.90±2.28; p<0.05). Less variability in positioning accuracy for femoral flexion angle and tibial rotation was found with PSG, indicating a result closer to the planned position, but no significant differences in positioning accuracy were found. PSG allowed more accurate prediction of the femoral (PSG: 100%; control: 64%) and tibial (PSG: 79%; control 56%) component size. CONCLUSION: PSG led to adequate component positioning accuracy compared to the pre-operative plan. For the femoral component, the positioning was significantly closer to the planned position in the coronal plane, a similar trend was observed for the sagittal plane. But, for the tibial component, significantly more slope was introduced. A better prediction of component sizing was found with PSG compared to conventional surgery.

Treatment of Painful, Irreparable Partial Meniscal Defects With a Polyurethane Scaffold: Midterm Clinical Outcomes and Survival Analysis.

BACKGROUND: A biodegradable polyurethane scaffold was designed to fulfill a challenging clinical need in the treatment of patients with painful, irreparable partial meniscal defects. HYPOTHESIS: The use of an acellular polyurethane scaffold for new tissue generation in irreparable, partial meniscal defects provides both midterm pain relief and improved functionality. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 44 patients with irreparable, partial meniscal defects (29 medial and 15 lateral) were implanted with a polyurethane scaffold in a prospective, single-arm proof-of-principle study with a minimum 5-year follow-up. Clinical outcomes were measured with the visual analog scale (VAS) for pain, International Knee Documentation Committee (IKDC), and Knee injury and Osteoarthritis Outcome Score (KOOS) at baseline and at 2- and 5-year follow-up. Magnetic resonance imaging (MRI) was used to evaluate the meniscal implant and cartilage status of the index compartment. Kaplan-Meier time-to-treatment failure distributions were also performed. Removal of the scaffold, conversion to a meniscal transplant, or unicompartmental/total knee arthroplasty was used as endpoints. RESULTS: Seven patients were lost to follow-up (15.9%). The patients who participated in this study showed significant clinical improvement after surgery (mean [±SD] at baseline, 2 years, and 5 years: 56.2 ± 21.6, 24.6 ± 22.7, and 19.3 ± 26.9, respectively [VAS]; 206.5 ± 79.7, 329.8 ± 108.9, and 333.6 ± 112.2, respectively [total KOOS]). MRI of the scaffolds showed a smaller sized implant when compared with the native meniscus with an irregular surface at 2- and 5-year follow-up. A stable cartilage status of the index compartment at 5-year follow-up was demonstrated in 46.7% of patients compared with the baseline status. During the follow-up period, 62.2% of the implants survived. At final follow-up, 66.7% of the medial scaffolds were still functioning versus 53.8% of the lateral scaffolds. CONCLUSION: A polyurethane meniscal implant can improve knee joint function and significantly reduce pain in patients with segmental meniscus deficiency up to 5 years after implantation. A stable cartilage status of the index compartment at 5-year follow-up was demonstrated in 46.7% of patients, calling into question the chondroprotective ability of the implant. In addition, a relatively high failure rate was noticed. Long-term and randomized controlled studies are mandatory to confirm the initial results and the reliability of this procedure.

Distinct dysregulation of the small leucine-rich repeat protein family in osteoarthritic acetabular labrum compared to articular cartilage.

OBJECTIVE: Articular cartilage is well studied in osteoarthritis (OA). However, the role of supporting structures, such as the acetabular labrum, a sealing structure surrounding the hip joint, has been investigated much less. We recently showed that fibrochondrocytic labrum cells are metabolically active. This study was undertaken to investigate hip OA­associated changes in human acetabular labrum cells. METHODS: Microarray analysis was performed to compare OA labrum cells to healthy labrum cells cultured in a 3-dimensional alginate bead system. Data were analyzed by cluster analysis using gene set enrichment analysis software and by gene list analysis using PANTHER gene family tools. Selected candidates were validated by quantitative polymerase chain reaction analysis on labrum and cartilage samples and by immunohistochemistry. The functional impacts of the genes identified were investigated by in vitro stimulation experiments in labrum cells. RESULTS: Pathway analysis revealed increased cytokine and chemokine signaling in OA labrum cells, whereas reduced extracellular matrix interactions and transforming growth factor ß signaling were observed. Several genes were significantly differentially expressed in OA compared to healthy labrum. We specifically focused on 3 small leucine-rich repeat proteins (SLRPs), osteomodulin, osteoglycin, and asporin, that appeared to be distinctly regulated in OA labrum compared to OA cartilage. SLRPs were strongly down-regulated in OA labrum but up-regulated in OA articular chondrocytes. Moreover, in vitro stimulation with osteomodulin increased aggrecan expression in OA labrum cells. CONCLUSION: OA labrum fibrochondrocytes have several features similar to OA chondrocytes. However, SLRP expression seems to be differentially influenced by degeneration in OA labrum compared to cartilage, suggesting a specific role for this supporting structure in OA. The functional impact of SLRPs on labrum cells makes them interesting targets for further studies in hip OA.

Midterm results of the treatment of cartilage defects in the knee using alginate beads containing human mature allogenic chondrocytes.

BACKGROUND: The treatment of chondral lesions is still an important challenge for the orthopaedic surgeon. Attempts have been made to restore cartilage lesions by filling the defects with a temporary biocompatible matrix. PURPOSE: The authors present their midterm experience with the implantation of alginate beads containing human mature allogenic chondrocytes for the treatment of cartilage lesions in the knee. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A biodegradable, alginate-based biocompatible scaffold containing human mature allogenic chondrocytes was used for the treatment of cartilage lesions in the knee. Twenty-one patients were clinically prospectively evaluated with use of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and a visual analog scale (VAS). The mean follow-up time was 6.3 years (range, 5-8 years). Magnetic resonance imaging (MRI) data were analyzed based on the MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) system, allowing morphologic assessment of the repair tissue. Magnetic resonance images were taken at 1 year of follow-up and at a mean follow-up of 6.1 years (range, 5-7 years). RESULTS: During the follow-up period, the WOMAC and VAS scores improved significantly. No signs of clinical deterioration or adverse reactions to the alginate beads/allogenic chondrocyte implantation were observed. Four failures occurred during the follow-up period in this study (19.05%). The MOCART scores were moderate and remained stable in time. CONCLUSION: This investigation provided useful information on the efficacy of the implantation of alginate beads containing human mature allogenic chondrocytes for the treatment of cartilage lesions in the knee. The midterm clinical outcome of the presented technique was satisfactory. However, these results were not confirmed by the MRI findings.