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.

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.

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.

Revision of meniscal transplants: long-term clinical follow-up.

PURPOSE: The primary aim is to document objective and subjective clinical outcome after knee arthroplasty for failed meniscal allograft transplantation; secondly, to investigate the influence of previous meniscal allograft surgery on the clinical outcome after a knee arthroplasty procedure; thirdly, to identify possible prognostic factors for the failure of meniscal allograft, such as potential number of concomitant procedures or pre-transplantation HSS-scores. The study population was compared to a control group of primary total knee arthroplasties. METHODS: The pre-operative phase, prior to meniscal allograft transplantation, was evaluated by the HSS questionnaire. At final follow-up, the clinical outcome was evaluated by the HSS, KOOS and SF-36 questionnaires. The mean follow-up was 16 years and 2 months. The control group, matched for age and sex, comprised patients with primary total knee arthroplasty. RESULTS: Statistical analysis showed that for the HSS-scores, there was no significant difference between the study population and the control group. KOOS data showed that the control group scored better overall. There was no significant difference between the HSS-scores after the transplantation and after the knee prosthesis. However, both showed a significant improvement regarding the clinical condition before meniscal transplantation. CONCLUSIONS: The clinical results after revised meniscal transplantation by means of knee prosthesis are highly variable with a tendency to have a lower score than patients with a primary knee prosthesis. Patients who underwent a revision of their meniscal allograft transplantation by means of a knee arthroplasty still had a significant better clinical outcome than prior to the meniscal allograft transplantation. There were no prognostic factors found by which one can determine whether a meniscal allograft will have a good survival or not.

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.

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.

The intra- and inter-observer reliability of the physical examination methods used to assess patients with patellofemoral joint instability.

BACKGROUND: An accurate physical examination of patients with patellar instability is an important aspect of the diagnosis and treatment. While previous studies have assessed the diagnostic accuracy of such physical examination tests, little has been undertaken to assess the inter- and intra-tester reliability of such techniques. The purpose of this study was to determine the inter- and intra-tester reliability of the physical examination tests used for patients with patellar instability. METHODS: Five patients (10 knees) with bilateral recurrent patellar instability were assessed by five members of the International Patellofemoral Study Group. Each surgeon assessed each patient twice using 18 reported physical examination tests. The inter- and intra-observer reliability was assessed using weighted Kappa statistics with 95% confidence intervals. RESULTS: The findings of the study suggested that there were very poor inter-observer reliability for the majority of the physical tests, with only the assessments of patellofemoral crepitus, foot arch position and the J-sign presenting with fair to moderate agreement respectively. The intra-observer reliability indicated largely moderate to substantial agreement between the first and second tests performed by each assessor, with the greatest agreement seen for the assessment of tibial torsion, popliteal angle and the Bassett's sign. CONCLUSIONS: For the common physical examination tests used in the management of patients with patellar instability inter-observer reliability is poor, while intra-observer reliability is moderate. Standardization of physical exam assessments and further study of these results among different clinicians and more divergent patient groups is indicated.

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.

Clinical Outcomes of Characterized Chondrocyte Implantation.

OBJECTIVE: To assess the clinical outcome of patients treated with autologous chondrocyte implantation using ChondroCelect in daily practice. METHODS: The study is a cross-sectional analysis of an open-label, noninterventional cohort. The setting was a compassionate use program, involving 43 orthopaedic centers in 7 European countries. The participants were patients treated with ChondroCelect between October 13, 2004 and July 2, 2008. The measurements used were Clinical Global Impression-Improvement and -Efficacy and solicited adverse event reports. RESULTS: Safety data were collected from 334 patients (90.3%), and effectiveness data were from 282 (76.2%) of the 370 patients treated. Mean age at baseline was 33.6 years (range, 12-57 years), 57% were male, and mean body mass index was 25 kg/m(2). Mean follow-up was 2.2 years (range, 0.4-4.1 years). A femoral condyle lesion was reported in 66% (288/379) and a patellar lesion in 19% (84/379). Mean lesion size was 3.5 cm(2); a collagen membrane was used in 92.4% (328/355). A therapeutic effect was reported in 89% (234/264) of patients overall and in 87% (40/46) of patellar lesion patients. Rates of much or very much improved patients were similar in patients with short- (<18 months: 71% [115/163]) and long-term follow-up (>18 months: 68% [70/103]) (P = 0.68) and were independent of lesion size (>4 cm(2): 75.5% [37/49]; ≤4 cm(2): 67.7% [111/164]) (P = 0.38). Adverse events were similar to those reported in the randomized trial with the same product, with more arthrofibrosis, more reduced joint mobility, and more crepitations reported in patellar lesions. Overall, less cartilage hypertrophy was noted, probably due to the use of a biological membrane cover. CONCLUSIONS: Implantation of ChondroCelect appeared to result in a positive benefit/risk ratio when used in an unselected heterogenous population, irrespective of the follow-up period, lesion size, and type of lesion treated.

Five-year outcome of characterized chondrocyte implantation versus microfracture for symptomatic cartilage defects of the knee: early treatment matters.

BACKGROUND: Characterized chondrocyte implantation (CCI) results in significantly better early structural tissue regeneration than microfracture (MF), and CCI has a midterm clinical benefit over microfracture. PURPOSE: This study was undertaken to evaluate the 5-year clinical outcome of CCI in a randomized comparison with MF for the treatment of symptomatic cartilage defects of the femoral condyles of the knee. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Participants aged 18 to 50 years with a symptomatic isolated International Cartilage Repair Society (ICRS) grade III or IV cartilage lesion of the femoral condyles between 1 and 5 cm(2) were randomized to either CCI or MF. Clinical outcomes were measured up to 60 months after surgery using the Knee Injury and Osteoarthritis Outcome Score (KOOS). The main outcome parameter was change from baseline in overall KOOS (oKOOS). Adverse events were monitored. RESULTS: Fifty-one participants were treated with CCI and 61 with MF. On average, clinical benefit was maintained through the 60-month follow-up period. The average change from baseline in oKOOS was not different between both groups (least squares [LS] mean ± standard error [SE] 18.84 ± 3.58 for CCI vs 13.21 ± 5.63 for MF; P = .116). Treatment failures were comparable (n = 7 in CCI vs n = 10 in MF), although MF failures tended to occur earlier. Subgroup analysis revealed that CCI resulted in better outcome in participants with time since symptom onset of less than 3 years, which was statistically significant and clinically relevant (change in oKOOS <3 years mean ± SE 25.96 ± 3.45 for CCI vs 15.28 ± 3.17 for MF; P = .026 vs oKOOS >3 years mean ± SE 13.09 ± 4.78 for CCI vs 17.02 ± 4.50 for MF, P = .554). Other subgroup analyses such as age (cutoff 35 years) did not show a difference. Female patients showed more failures irrespective of treatment. CONCLUSION: At 5 years after treatment, clinical outcomes for CCI and MF were comparable. In the early treatment group, CCI obtained statistically significant and clinically relevant better results than MF. Delayed treatment resulted in less predictable outcomes for CCI. These results provide strong evidence that time since onset of symptoms is an essential variable that should be taken into account in future treatment algorithms for cartilage repair of the knee.

The effect of Lidocaine on the viability of cultivated mature human cartilage cells: an in vitro study.

PURPOSE: More and more orthopedic procedures are performed in an outpatient setting. A commonly used strategy in pain management is the intra-articular injection of local anesthetics. Recent attention has been drawn to their possible toxic effect on chondrocytes. Local anesthetics, and in particular Lidocaine, are also used for diagnostic joint infiltrations. A controlled laboratory study was performed to investigate the possible toxic effect of Lidocaine on human articular chondrocytes. METHODS: Mature human articular chondrocytes were harvested from the knees of human tissue donors or patients undergoing total knee replacement. The cells were exposed to Lidocaine 1 and 2% with and without epinephrine and to a saline 0.9% control group, with variable exposure times in different experiments. The activity and viability of the cells were assessed by lactate dehydrogenase activity, interleukin-6 production and a live/dead cell count. RESULTS: After a 1-h exposure, devastating results were seen for Lidocaine 1, 2 and 2% with epinephrine showing cell death rates of 91, 99 and 97%, respectively, compared with 26% in the saline control group (P-values of 0.004, 0.010, 0.006, respectively). Exposing the chondrocytes to a 50/50 mixture of culture medium and local anesthetics substantially decreased cytotoxicity but still showed high toxicity when compared with the saline group (90% dead cells for Lidocaine 2%, P = 0.047). Lidocaine also showed a time-dependent cytotoxicity with gradually more dead cells after exposure for 15, 30 or 60 min. CONCLUSION: In vitro, local anesthetics containing Lidocaine are significantly more toxic to mature human articular chondrocytes than a saline 0.9% control group. The effect of Lidocaine on the viability of human chondrocytes in vivo needs further investigation. However, based on our in vitro results, cautious use of intra-articular Lidocaine in clinical practice is recommended.

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.

Treatment of symptomatic cartilage defects of the knee: characterized chondrocyte implantation results in better clinical outcome at 36 months in a randomized trial compared to microfracture.

BACKGROUND: Damaged articular cartilage has limited capacity for self-repair. Autologous chondrocyte implantation using a characterized cell therapy product results in significantly better early structural repair as compared with microfracture in patients with symptomatic joint surface defects of the femoral condyles of the knee. PURPOSE: To evaluate clinical outcome at 36 months after characterized chondrocyte implantation (CCI) versus microfracture (MF). STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Patients aged 18 to 50 years with single International Cartilage Repair Society (ICRS) grade III/IV symptomatic cartilage defects of the femoral condyles were randomized to CCI (n = 57) or MF (n = 61). Clinical outcome was measured over 36 months by the Knee injury and Osteoarthritis Outcome Score (KOOS). Serial magnetic resonance imaging (MRI) scans were scored using the Magnetic resonance Observation of Cartilage Repair Tissue (MOCART) system and 9 additional items. Gene expression profile scores associated with ectopic cartilage formation were determined by RT-PCR. RESULTS: Baseline mean overall KOOS (+/-SE) was comparable between the CCI and MF groups (56.30 +/- 1.91 vs 59.46 +/- 1.98, respectively). Mean improvement (+/-SE) from baseline to 36 months in overall KOOS was greater in the CCI group than the MF group (21.25 +/- 3.60 vs 15.83 +/- 3.48, respectively), while in a mixed linear model analysis with time as a categorical variable, significant differences favoring CCI were shown in overall KOOS (P = .048) and the subdomains of Pain (P = .044) and QoL (P = .036). More CCI- than MF-treated patients were treatment responders (83% vs 62%, respectively). In patients with symptom onset of <2 years, the mean improvement (+/-SE) from baseline to 36 months in overall KOOS was greater with CCI than MF (24.98 +/- 4.34 vs 16.50 +/- 3.99, respectively) and even greater in patients with symptom onset of <3 years (26.08 +/- 4.10 vs 17.09 +/- 3.77, respectively). Characterized chondrocyte implantation patients with high (> or =2) versus low (<2) gene profile scores showed greater improvement from baseline in mean overall KOOS (+/-SE) at 36 months (28.91 +/- 5.69 vs 18.18 +/- 5.08, respectively). Subchondral bone reaction significantly worsened over time with MF compared with CCI (P <.05). CONCLUSION: Characterized chondrocyte implantation for the treatment of articular cartilage defects of the femoral condyles of the knee results in significantly better clinical outcome at 36 months in a randomized trial compared with MF. Time to treatment and chondrocyte quality were shown to affect outcome.

Treatment of cartilage defects in the knee using alginate beads containing human mature allogenic chondrocytes.

BACKGROUND: The repair of osteochondral lesions is imperfect and transient; chondral lesions do not heal in mature cartilage. Attempts have been made to restore cartilage lesions by filling the defects with a temporary artificial biocompatible matrix. PURPOSE: To determine whether the implantation of alginate beads containing human mature allogenic chondrocytes is feasible and safe for the treatment of symptomatic cartilage defects 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 chondral and osteochondral lesions in the knee. Twenty-one patients were clinically and prospectively evaluated with use of the Western Ontario and McMaster Universities Osteoarthritis Index and a visual analog scale for pain preoperatively and at 3, 6, 9, 12, 18, and 24 months of follow-up. Of the 21 patients, 13 consented to having a biopsy sample taken for investigative purposes from the area of implantation at 12 months of follow-up, allowing histologic assessment of the repair tissue. RESULTS: A statistically significant clinical improvement became apparent after 6 months, and patients improved during the 24 months of follow-up. Adverse reactions to the alginate/fibrin matrix seeded with the allogenic cartilage cells were not observed. Histologic analysis of the biopsy specimens rated the repair tissue as hyaline-like in 15.3% of the samples, as mixed tissue in 46.2%, as fibrocartilage in 30.8%, and as fibrous in 7.7%. CONCLUSION: The results of this short-term pilot study show that the alginate-based scaffold containing human mature allogenic chondrocytes is feasible and safe for the treatment of symptomatic cartilage defects of the knee. The described technique provides clinical and histologic outcomes that are equal but not superior to those of other cartilage repair techniques.

Viable meniscal transplantation / Viabilidade do transplante meniscal

Restoring the normal congruency between femur and tibia with intact menisci could be a solution to many mechanical knee problems. Good functional results have been achieved with the transplantation of menisci in compartmental meniscal degeneration, However, this type of chonrotection can only be evaluated after 10 to 20 years of follow-up. Satisfactory incorporation of meniscal transplants has been obtained with fresh allografts, but availability remains a problem with this method of meniscal substitution. Incorporation and ingrowth of fibroblasts have been shown in cryopreserved and deep-frozen meniscal allografts. In a small number of transplants shrinking has been observed on repeat arthroscopy. Since 1989, viable meniscal allograftng has been performed in a series of more than 200 patients. The value of this method has been studied. With the use of a semisynthetic medium the semilunar cartilages can be kept viable without apparent loss of fibrochondroblast cell activity. During this incubation period the appropriate recipient can be ed and prepared. There is sufficient time to conduct a laboratory screening and to evaluate the culture results and desease transmission factors. In this way, live transplant hazards can be avoided, resulting in a higher success rate. The knee is a weight-bearing joint. The patient himself is responsable for mechanical loading, and medical control of these conditions is not always possible. The intensity of loading thus remains an aspect that cannot always be determined scientifically and must be considered in pathology. In view of the promising of the promising results obtained with tendon allografts and with meniscal allografts in sheep(1), meniscus transplantation in humans has become an attractive treatment option. Meniscus transplantation involves the necessity to store and preserve meniscal material.

O restabelecimento da normalidade congruência entre o fêmur e a tíbia com meniscos intactos poderia ser uma solução para muitos problemas mecânicos do joelho. Bons resultados funcionais foram obtidos com o transplante de meniscos nas degenerações compartimentais pós-meniscectomia, no entanto, este tipo de conroteção só poderá ser avaliada após 10 a 20 anos de seguimento...

Silkworm and spider silk scaffolds for chondrocyte support.

OBJECTIVE: To create scaffolds with silkworm cocoon, spider egg sac and spider dragline silk fibres and examine their use for chondrocyte attachment and support. METHODS: Three different kinds of scaffolds were developed with Bombyx mori cocoon, Araneus diadematus egg sac and dragline silk fibres. The attachment of human articular cartilage cells were investigated on these bioprotein matrices. The chondrocytes produced an extracellular matrix which was studied by immunostaining. Moreover, the compression behaviour in relation to the porosity was studied. RESULTS: The compression modulus of a silkworm silk scaffold was related to its porosity. Chondrocytes were able to attach and to grow on the different fibres and in the scaffolds for several weeks while producing extracellular matrix products. CONCLUSION: Porous scaffolds can be made out of silkworm and spider silk for cartilage regeneration. Mechanical properties are related to porosity and pore size of the construct. Cell spreading and cell expression depended on the porosity and pore-size.

Knee arthrodesis with an intramedullary nail: a retrospective study.

A group of 19 patients who underwent knee arthrodesis with use of an intramedullary nail between 1996 and 2005, was studied. In the majority of patients knee arthrodesis was performed as a salvage procedure for the limb following an infected total knee arthroplasty. The outcome of the procedure was evaluated with radiographs, the SF-36 score and the Oxford 12-item knee score. The functional result of a successful arthrodesis was found to be comparable with that of a revised hinged total knee arthroplasty. Knee arthrodesis with an intramedullary nail allows weightbearing within 1 week and is accompanied by a high rate of pain relief. However, recurrence of infection is the most challenging problem.

Biocompatibility and biodegradability of spider egg sac silk.

Spider egg sac silk (SpESS) were enzymatically cleaned and their biodegradation in vivo and in vitro, as well as their biocompatibility were studied. Proteinase K treatment diminished the tenacity and the strain of the SpESS fibers in proportion to the enzyme concentration. Fibers treated with trypsin were not significantly affected. Tensile properties of Vicryl, SpESS and of silkworm (Bombyx mori) silk fibers (SWS) were measured after incubation in phosphate buffered saline (PBS) at 37 degrees C up to 12 weeks. Biodegradation of SpESS and SWS was insignificant compared to Vicryl. Five milligram SpESS fibers from laboratory grown spiders (Araneus diadematus) were treated with proteinases before sterilization and subcutaneously implanted in Wistar rats. After 1, 4 and 7 weeks the immunological reaction was compared to untreated SpESS and polyglactin (Vicryl) control samples. SpESS samples treated with trypsin only or in combination with a Proteinase K treatment induced less inflammatory reactions than untreated silk fibers. The enzymatical cleaning could diminish the tensile properties, but enhanced the biocompatibility of the SpESS fibers rendering them appropriate for use in biomaterial application where the slow biodegradability is an advantage.

Traumatic proximal tibiofibular dislocation.

Traumatic proximal tibiofibular dislocation is a rare injury that is often unrecognized or misdiagnosed at the initial presentation because of a lack of clinical suspicion. When diagnosed, the injury should be promptly reduced. Missed injuries or late presentations are a potential source of chronic morbidity. This article describes the relevant anatomy, classifications, and diagnostic and therapeutic approaches. The authors stress the importance of evaluating the distal syndesmotic ligaments and the interosseous membrane because the mechanism of trauma can also cause a disruption of the distal tibiofibular syndesmosis. In the presence of syndesmotic instability, prompt stabilization is advocated. Whether syndesmotic stabilization is indicated in cases of a syndesmotic sprain is controversial. An illustrative case is also presented of a 28-year-old male soccer player who sustained a proximal tibiofibular dislocation after a violent twisting motion of the right knee.

Meniscal allografts: indications and outcomes.

Meniscal allograft transplantation was introduced into clinical practice now over 20 years ago for the treatment of the symptomatic postmeniscectomy patient who has not yet developed osteoarthritis. Over the years, the indications have been fine-tuned and certain risk factors for failure have been identified. As the number of publications increases steadily, we now know that meniscal allografting significantly reduces pain and improves function. Recent data also suggest a potential chondroprotective effect in a subpopulation of patients. However, the major drawback in all meniscus allograft studies is the general lack of a control population. To improve our knowledge, future prospective studies should include objective outcome tools to evaluate the status of the allograft in addition to the clinical scoring systems. Future research should focus to elucidate the biologic and cellular processes involved in graft repopulation and remodelation.