Does smoking influence outcome after autologous chondrocyte implantation?

Surgical Management of Failed Articular Cartilage Surgery in the Knee

Failure rates of cartilage restoration surgery range from 14% to 43%. When failure of prior cartilage restoration surgery is suspected, a thorough clinical workup should be performed to assess the timing and duration of symptoms. Attention should be paid to patient risk factors such as age, body mass index, and smoking status. Concomitant pathology such as malalignment, ligament insufficiency, and meniscus status must be evaluated before revision surgery. As outlined in our treatment algorithm, the size/location of the lesion and the type of primary procedure will guide planning for revision procedures. [Orthopedics. 2023;46(5):262-272.].

Typical Complications After Cartilage Repair of the Ankle Using Autologous Matrix-Induced Chondrogenesis (AMIC)

Background:

Autologous matrix-induced chondrogenesis (AMIC) for the treatment of osteochondral lesions of the talus (OLT) results in favorable clinical outcomes, yet high reoperation rates. The aim of this study was to report and analyze typical complications and their risk factors after AMIC for OLT.

Methods:

A total of 127 consecutive patients with 130 AMIC procedures for OLT were retrospectively assessed. All AMIC procedures were performed in an open fashion with 106 (81.5%) cases requiring a malleolar osteotomy (OT) to access the OLT. Seventy-one patients (54.6%) underwent subsequent surgery. These cases were evaluated at a mean follow-up of 3.1 years (±2.5) for complications reviewing postoperative imaging and intraoperative findings during revision surgery. Six patients (8.5%) were lost to follow-up. Regression model analysis was conducted to identify factors that were associated with AMIC-related complications.

Results:

Among the 65 (50%) patients who required revision surgery, 18 patients (28%) demonstrated AMIC-related complications with deep fissuring (83%) and thinning (17%) of the AMIC graft. Conversely, 47 patients (72%) underwent subsequent surgery due to AMIC-unrelated reasons including isolated removal of symptomatic hardware (n = 17) and surgery addressing concomitant pathologies with (n = 25) and without hardware removal (n = 5). Previous prior cartilage repair surgery was significantly associated with AMIC graft-associated complications in patients undergoing revision surgery ( P = .0023). Among age, body mass index, defect size, smoking, and bone grafting, smoking was the only factor showing statistical significance with an odds ratio of 3.7 (95% CI 1.24, 10.9; P = .019) to undergo revision surgery due to graft-related complications, when adjusted for previous cartilage repair surgery.

Conclusion:

The majority of revision surgeries after AMIC for OLT are unrelated to the performed AMIC graft but frequently address symptomatic hardware and concomitant pathologies. Both smoking and previous cartilage repair surgery seem to significantly increase the risk of undergoing revision surgery due to AMIC-related complications.

Level of evidence:

Level IV, case series.

The Effect of Smoking on the Outcome of Matrix-Based Autologous Chondrocyte Implantation: Data from the German Cartilage Registry

Smoking is known to have various deleterious effects on health. However, it is not clear whether smoking negatively affects the postoperative outcome following matrix-based autologous cartilage implantation (MACI) in the knee. The purpose of this study was to evaluate the effect of smoking on the outcome of MACI in the knee. A total of 281 patients receiving MACI in the knee between 2015 and 2018 were registered in the German Cartilage Database. The cohort was divided into ex-smokers, smokers, and nonsmokers. Data regarding the Knee Injury and Osteoarthritis Outcome Score (KOOS), the numeric rating scale (NRS) for pain, and satisfaction with the outcome were analyzed and compared. Follow-ups were performed at 6, 12, and 24 months after surgery. Of the 281 patients, 225 (80.1%) were nonsmokers, 43 (15.3%) were smokers, and 13 (4.6%) were ex-smokers. The three groups were comparable with respect to age, sex, body mass index (BMI), height, defect size, the need for additional reconstruction of the subchondral bone defect, number of previous knee surgeries, and defect location. However, nonsmokers had a significantly lower weight as compared with smokers. Besides a significantly lower preoperative NRS of nonsmokers as compared with smokers, there were no significant differences between the three groups with respect to KOOS, NRS, and satisfaction at 6, 12, and 24 months of follow-ups. The present study of data retrieved from the German Cartilage Registry suggests that the smoking status does not influence the outcome of MACI in the knee.

Utilization of Autologous Chondrocyte Implantation in the Knee is Increasing While Reoperation Rates Are Decreasing Despite Increasing Preoperative Comorbidities

PURPOSE

The primary purpose of this study was to assess the use of autologous chondrocyte implantation (ACI) procedures in the knee during last decade, and the secondary aims of the study were to determine reoperation rates after ACI and to identify associated risk factors.

METHODS

A retrospective cohort study from 2010-2020 was performed using the PearlDiver database. The database was queried for the Current Procedural Terminology (CPT) code for ACI performed in any knee location, including the patellofemoral and tibiofemoral joints. Reoperation was defined as interventional knee procedures or total knee arthroplasty after ACI. Reoperations were identified using CPT and International Classification of Diseases codes. Univariate and multivariate logistic regression were used to identify risk factors for reoperation. Significance was defined as P < .05.

RESULTS

Among the 2010 patients included in this study, there were 90-day and overall reoperation rates of 2.24% and 30.4%, respectively, with an average follow up of 4.8 ± 3.3 years. The most common reoperations included chondroplasty, meniscectomy, and microfracture. There was an increased rate of ACI performed from 2017-2019 (5.53/100,000) compared to 2014-2016 (4.16/100,000; P < .001). ACI surgeries performed in 2017-2019 were associated with decreased risk of reoperation within 2 years relative to 2014-2016 (odds ratio [OR] = 0.70; 95% confidence interval [CI], 0.52-0.94; P = .019). In the entire ACI cohort, older age (OR = 1.07; 95% CI, 1.05-1.09; P < .001) and tobacco use (OR = 2.13; 95% CI, 1.06-3.94; P = .022) were associated with increased risk of conversion to arthroplasty. Male sex was associated with decreased overall reoperation rates (OR = 0.73; 95% CI, 0.60-0.89; P = .002).

CONCLUSIONS

There has been increasing use of ACI in the knee with decreased risk of reoperation since 2017 and the introduction of matrix-associated autologous chondrocyte implantation. Older age and tobacco use were predictors of increased risk of conversion to arthroplasty. Male sex was associated with decreased risk of reoperation.

LEVEL OF EVIDENCE

Level IV, retrospective cohort design; database study.

Particulated Juvenile Articular Cartilage and Matrix-Induced Autologous Chondrocyte Implantation Are Cost-Effective for Patellar Chondral Lesions

PURPOSE

To compare the cost-effectiveness of nonoperative management, particulated juvenile allograft cartilage (PJAC), and matrix-induced autologous chondrocyte implantation (MACI) in the management of patellar chondral lesions.

METHODS

A Markov model was used to evaluate the cost-effectiveness of three strategies for symptomatic patellar chondral lesions: 1) nonoperative management, 2) PJAC, and 3) MACI. Model inputs (transition probabilities, utilities, and costs) were derived from literature review and an institutional cohort of 67 patients treated with PJAC for patellar chondral defects (mean age 26 years, mean lesion size 2.7 cm²). Societal and payer perspectives over a 15-year time horizon were evaluated. The principal outcome measure was the incremental cost-effectiveness ratio (ICER) using a $100,000/quality-adjusted life year (QALY) willingness-to-pay threshold. Sensitivity analyses were performed to assess the robustness of the model and the relative effects of variable estimates on base case conclusions.

RESULTS

From a societal perspective, nonoperative management, PJAC, and MACI cost $4,140, $52,683, and $83,073 and were associated with 5.28, 7.22, and 6.92 QALYs gained, respectively. PJAC and MACI were cost-effective relative to nonoperative management (ICERs $25,010/QALY and $48,344/QALY, respectively). PJAC dominated MACI in the base case analysis by being cheaper and more effective, but this was sensitive to the estimated effectiveness of both strategies. PJAC remained cost-effective if PJAC and MACI were considered equally effective.

CONCLUSIONS

In the management of symptomatic patellar cartilage defects, PJAC and MACI were both cost-effective compared to nonoperative management. Because of the need for one surgery instead of two, and less costly graft material, PJAC was cheaper than MACI. Consequently, when PJAC and MACI were considered equally effective, PJAC was more cost-effective than MACI. Sensitivity analyses accounting for the lack of robust long-term data for PJAC or MACI demonstrated that the cost-effectiveness of PJAC versus MACI depended heavily on the relative probabilities of yielding similar clinical results.

LEVEL OF EVIDENCE

III, economic and decision analysis.

Mood Disorders Are Associated with Increased Perioperative Opioid Usage and Health Care Costs in Patients Undergoing Knee Cartilage Restoration Procedure

OBJECTIVE

To identify the prevalence of mood disorder diagnoses in patients undergoing cartilage transplantation procedures and determine the relationship between mood disorders, opioid usage, and postoperative health care costs.

DESIGN

Patients with current procedural terminology (CPT) codes for osteochondral autograft transplantation (OAT), osteochondral allograft transplantation (OCA), and autologous chondrocyte implantation (ACI) were identified in the Truven Health Marketscan database (January 2009-September 2014). Patients were grouped based on having a preoperative mood disorder diagnosis (preMDD). Preoperative opioids, postoperative opioids ≥90 days, and health care costs within the year postoperative were compared for those with and without mood disorders. Costs were analyzed, adjusting for preoperative cost, sex, age, and opioid usage, for those with and without mood disorders.

RESULTS

A total of 3,682 patients were analyzed (ACI: 690, OAT: 1,294, OCA: 1,698). A quarter of patients had preMDD (ACI: 25.4%, OAT: 20.6%, OCA: 22.7%). Postoperative opioid use was more prevalent in preMDD patients (OAT: 37.1% vs. 24.1%, P < 0.001; OCA: 30.4% vs. 24.8%, P = 0.032; ACI: 33.7% vs. 26.2%, P = 0.070) (odds ratio [OR] ranged from 1.29 to 1.86). First-year postoperative log-transformed costs were significantly greater for preMDD patients (ACI: $7,733 vs. $5,689*, P = 0.012; OAT: $5,221 vs. $3,823*, P < 0.001; OCA: $6,973 vs. $3,992*, P < 0.001; *medians reported). The estimated adjusted first postoperative year cost increase for preMDD OCA patients was 41.7% (P < 0.001) and 28.0% for OAT patients (P = 0.034). There was no statistical difference for ACI patients (P = 0.654).

CONCLUSION

Cartilage transplantation patients have a high prevalence of preoperative mood disorders. Opioid use and health care costs were significantly greater for patients with preoperative mood disorder diagnoses.

LEVEL OF EVIDENCE

Level III, retrospective therapeutic study.

Smoking Is Associated with Anterior Ankle Impingement After Isolated Autologous Matrix-Induced Chondrogenesis for Osteochondral Lesions of the Talus

OBJECTIVE

To determine potential predictive associations between patient-/lesion-specific factors, clinical outcome and anterior ankle impingement in patients that underwent isolated autologous matrix-induced chondrogenesis (AMIC) for an osteochondral lesion of the talus (OLT).

DESIGN

Thirty-five patients with a mean age of 34.7 ± 15 years who underwent isolated cartilage repair with AMIC for OLTs were evaluated at a mean follow-up of 4.5 ± 1.9 years. Patients completed AOFAS (American Orthopaedic Foot and Ankle Society) scores at final follow-up, as well as Tegner scores at final follow-up and retrospectively for preinjury and presurgery time points. Pearson correlation and multivariate regression models were used to distinguish associations between patient-/lesion-specific factors, the need for subsequent surgery due to anterior ankle impingement and patient-reported outcomes.

RESULTS

At final follow-up, AOFAS and Tegner scores averaged 92.6 ± 8.3 and 5.1 ± 1.8, respectively. Both body mass index (BMI) and duration of symptoms were independent predictors for postoperative AOFAS and Δ preinjury to postsurgery Tegner with positive smoking status showing a trend toward worse AOFAS scores, but this did not reach statistical significance (P = 0.054). Nine patients (25.7%) required subsequent surgery due to anterior ankle impingement. Smoking was the only factor that showed significant correlation with postoperative anterior ankle impingement with an odds ratio of 10.61 when adjusted for BMI and duration of symptoms (95% CI, 1.04-108.57; P = 0.047).

CONCLUSION

In particular, patients with normal BMI and chronic symptoms benefit from AMIC for the treatment of OLTs. Conversely, smoking cessation should be considered before AMIC due to the increased risk of subsequent surgery and possibly worse clinical outcome seen in active smokers.

Comparison of Autologous Chondrocyte Implantation and Osteochondral Allograft Transplantation of the Knee in a Large Insurance Database: Reoperation Rate, Complications, and Cost Analysis

OBJECTIVE

To compare (1) the reoperation rates, (2) risk factors for reoperation, (3) 30-day complication rates, and (4) cost differences between autologous chondrocyte implantation (ACI) and osteochondral allograft transplantation (OCA) of the knee in a large insurance database.

DESIGN

Subjects who underwent knee ACI (Current Procedural Terminology [CPT] code 27412) or OCA (CPT code 27415) with minimum 2-year follow-up were queried from a national insurance database. Reoperation was defined by ipsilateral knee procedure after index surgery. Multivariate logistic regression models were built to determine the effect of independent variables (age, sex, tobacco use, obesity, diabetes, and concomitant osteotomy) on reoperation rates. The 30-day complication rates were assessed using ICD-9-CM codes. The cost of the procedures per patient was calculated. Statistical comparisons were made. All P values were reported with significance set at P < 0.05.

RESULTS

A total of 909 subjects (315 ACI and 594 OCA) were included (mean follow-up 39.2 months). There was a significantly higher reoperation rate after index ACI compared with OCA (67.6% vs. 40.4%, P < 0.0001). Concomitant osteotomy at the time of index procedure significantly reduced the risk for reoperation in both groups (odds ratio [OR] 0.2, P < 0.0001 and OR 0.2, P = 0.009). The complication rates were similar between ACI (1.6%) and OCA (1.2%) groups (P = 0.24). Day of surgery payments were significantly higher after ACI compared with OCA (P = 0.013).

CONCLUSIONS

Autologous chondrocyte implantation had significantly higher reoperation rates and cost with similar complication rates compared with OCA. Concomitant osteotomy significantly reduced the risk for reoperation in both groups.

The Role of Hypertension in Cartilage Restoration: Increased Failure Rate After Autologous Chondrocyte Implantation but Not After Osteochondral Allograft Transplantation

Objectives. The purpose of this study was to examine whether patients with diagnosed hypertension have an increased risk of graft failure following cartilage repair with either autologous chondrocyte implantation (ACI) or osteochondral allograft transplantation (OCA). We hypothesized that hypertension is related to higher ACI and OCA graft failure. Design. Patients who underwent ACI or OCA transplantation between February 2009 and December 2016 were included in this study. Inclusion criteria were (1) at least 2 years' follow-up, (2) available information related to the living habits (smoking and medication status), and (3) available information related to the presence of hypertension, diabetes mellitus, or hyperlipidemia. To identify potential independent risk factors of graft failure, univariate screening was performed and factors with significance at a level of P < 0.1 were entered in multivariate logistic regression models. Results. A total of 368 patients (209 ACI and 159 OCA) were included into our study. In the ACI group, 61 patients' (29.1%) graft failed. Univariate screening identified older age, female gender, defect size, higher prevalence of hypertension, and smoking as a predictor of graft failure. Following, multivariate logistic regression revealed female gender (odds ratio [OR] 1.02, P = 0.048), defect size (OR 1.07, P = 0.035), and hypertension (OR 3.73, P = 0.023) as significant independent risk factors predicting graft failure after ACI. In the OCA group, 29 patients' (18.2%) graft failed and none of the included factors demonstrated to be a potential risk factor for graft failure. Conclusion. Hypertension, defect size, and female gender seem to predict ACI graft failure but not OCA failure.

Symptom Chronicity and Tobacco Use: Differences in Athletic and Nonathletic Candidates for Cartilage Surgery

OBJECTIVE

To determine whether there are differences in symptomatic knee cartilage defects and rates of tobacco use among age-matched athletes versus nonathletes undergoing initial arthroscopic knee surgery who meet demographic and radiographic criteria for cartilage restoration surgery.

DESIGN

Age-matched athletes (n = 186) and nonathletes (n = 159) age 40 or less with a body mass index (BMI) of 35 kg/m² or less (mean 26.8 SD 4.1) and <50% joint space narrowing on weight-bearing radiographs were included. All patients had a symptomatic Outerbridge grade 2 or higher cartilage defect visualized during knee arthroscopy. Relationship between athletic status and chronicity of knee symptoms prior to surgery and tobacco use status, cartilage defect Outerbridge grade, size, and location at time of surgery were characterized.

RESULTS

Nonathletes were more likely to smoke (P < 0.001) and had higher BMI (P = 0.005). Duration of symptoms prior to surgery was shorter among athletes (P < 0.001). Grade 4 defects were equally prevalent (P = 0.96) as were multicompartment grade 3-4 lesions (P = 0.12). Mean grade 3-4 defect size was similar in lateral (P = 0.96) and medial compartments (P = 0.82). There was a trend toward larger anterior compartment defects in nonathletes (P = 0.07).

CONCLUSIONS

Among age-matched athletes and nonathletes with symptomatic cartilage defects who meet demographic criteria for cartilage restoration, nonathletes were more likely to smoke and have a longer duration of symptoms prior to treatment. Athletes tended to present earlier but with similar size defects compared to nonathletes, supporting accelerated treatment of defects in athletes and caution toward allowing continued athletic participation in patients with known cartilage defects.

Predictors of postoperative pain using PROMIS pain interference two-years following knee surgery

Introduction

The purpose of this study was to identify preoperative factors associated with worse PROMIS Pain Interference (PI) two years following knee surgery.

Methods

Participants completed surveys preoperatively and two years postoperatively. Data collected included demographics, medical history, and multiple patient-reported outcomes measures, including PROMIS PI.

Results

After controlling for confounders, lower income, smoking, worse PROMIS Anxiety, worse Numeric Pain Score body pain, and worse Marx Activity Rating Scale were independent predictors for worse PROMIS PI two years after surgery.

Conclusion

Worse PROMIS PI two years after elective knee surgery is associated with multiple socio-demographic patient identifiers.

[Guidelines for the treatment of unicompartmental cartilage defects of the knee-Cartilage repair, osteotomy, mini-implant or arthroplasty?]

The treatment of unicompartmental cartilage defects offers a large variety of therapeutic options. With help of an algorithm, decision-making for the most suitable treatment approach is supported. Correction of malalignment is key for successful treatment. Defect size, influencing factors such as "age" and prior treatments play an important role in choosing the most appropriate operative treatment option.

Preoperative Mental Health Has a Stronger Association with Baseline Self-Assessed Knee Scores than Defect Morphology in Patients Undergoing Cartilage Repair

OBJECTIVE

The purpose of this study was to assess potential correlations between the mental component summary of the Short Form-12 (SF-12 MCS), patient characteristics or lesion morphology, and preoperative self-assessed pain and function scores in patients undergoing autologous chondrocyte implantation (ACI).

DESIGN

A total of 290 patients underwent ACI for symptomatic cartilage lesions in the knee. One hundred and seventy-eight patients were included in this study as they completed preoperative SF-12, Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner, Lysholm, and International Knee Documentation Committee (IKDC) scores. Age, sex, smoker status, body mass index, Worker's Compensation, previous surgeries, concomitant surgeries, number of defects, lesion location in the patella, and total defect size were recorded for each patient. Pearson's correlation and multivariate regression models were used to distinguish associations between these factors and preoperative knee scores.

RESULTS

The SF-12 MCS showed the strongest bivariate correlation with all KOOS subgroups (P < 0.001) (except KOOS Symptom; P = 0.557), Tegner (P = 0.005), Lysholm (P < 0.001), and IKDC scores (P < 0.001). In the multivariate regression models, the SF-12 MCS showed the strongest association with all KOOS subgroups (P < 0.001) (except KOOS Symptom; P = 0.91), Lysholm (P = 0.001), Tegner (P = 0.017), and IKDC (P < 0.001).

CONCLUSION

In patients with symptomatic cartilage defects of the knee, preoperative patient mental health has a strong association with self-assessed pain and functional knee scores. Further studies are needed to determine if preoperative mental health management can improve preoperative symptoms and postoperative outcomes.

Increased Chondrocytic Gene Expression Is Associated With Improved Repair Tissue Quality and Graft Survival in Patients After Autologous Chondrocyte Implantation

BACKGROUND

Assays to quantitate the quality of autologous chondrocyte implants have recently become available. However, the correlation of the assay score with radiological and clinical outcomes has not been established.

PURPOSE/HYPOTHESIS

The purpose was to assess the influence of cell identity (chondrocyte/synoviocyte gene expression ratio) and viability on patient-reported outcome measures, graft survival, and repair tissue quality. It was hypothesized that greater cell product quality as assessed through an identity assay and cell viability is associated with superior outcomes after autologous chondrocyte implantation (ACI) for symptomatic cartilage defects.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Seventy-nine patients with a minimum follow-up of 2 years were included in this study. Of these, 67 patients were available for imaging assessment utilizing the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system. Patients were assigned to groups either below or above the cohort's mean based on their individual cell identity score and viability percentage.

RESULTS

Patients were predominantly female (57.7%) with a mean age of 30.0 ± 9.3 years. No differences were seen between Knee injury and Osteoarthritis Outcome Score, Lysholm, Tegner, or International Knee Documentation Committee Subjective Knee Evaluation Form within the viability and cell identity groups at a final follow-up of 3.8 ± 1.4 years after ACI (P > .05). In a subset of patients, the mean MOCART score was 68.3 ± 15.6 at an average magnetic resonance imaging follow-up of 17.7 ± 9.56 months. Low cell identity was significantly associated with the degree of defect filling (P = .025), integration of border zone (P = .01), effusion (P = .024), and ACI graft failure (P = .002). Patients with above-average cell identity scores had a significantly higher survival rate at 5-year follow-up compared with patients with below-average scores (95.8% vs 64.7%; P = .013). Cell viability did not influence MOCART subscales or graft failure (all P > .05). Cell viability and identity showed no significant correlation with each other (r = -0.045; P = .694).

CONCLUSION

Cell identity was significantly correlated with structural repair quality and graft survival after second-generation ACI for symptomatic chondral lesions in the knee. While improved imaging outcome and higher graft survivorship were associated with a higher individual cell identity score indicating a higher chondrocyte/synoviocyte gene expression ratio in the final cell product, clinical outcome did not correlate with the identity score.

Autologous Chondrocyte Implantation and Tibial Tubercle Osteotomy for Patellofemoral Chondral Defects: Improved Pain Relief and Occupational Outcomes Among US Army Servicemembers

BACKGROUND

The occupational and functional results of patellofemoral autologous chondrocyte implantation (ACI) are underreported. This investigation sought to establish clinical outcomes and rates for return to work in a predominantly high-demand military cohort undergoing this procedure.

PURPOSE

To determine the return-to-work, pain relief, and perioperative complication rates in a high-demand athletic cohort undergoing patellofemoral ACI.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All military servicemembers from 2 military medical centers undergoing ACI for high-grade patellofemoral chondral defects between 2006 and 2014 were identified, and data were abstracted from their medical records and clinical databases. Demographic and surgical variables were obtained for patients with at least 2 years of postoperative follow-up, and perioperative complications, rates of return to work, and survivorship from revision were quantified.

RESULTS

Seventy-two patients (72%) had >2-year follow-up and had patellofemoral ACI for high-grade chondral defects, with 66 knees (91%) undergoing a concomitant offloading tibial tubercle osteotomy. Mean follow-up was 4.3 years (range, 2.0-9.9 years). The mean ± SD age was 34.4 ± 6.1 years; 86% were male; and 57% were involved in military occupational specialties of heavy or very heavy demand. Second-generation patellofemoral ACI with a type I/III collagen membrane was used for 85% of knees. Most defects were isolated to the patella (n = 40, 55%). The mean total defect surface area was 4.5 ± 2.9 cm² (range, 2.7-13.5 cm²). Fifty-six servicemembers (78%) returned to their occupational specialties. Three patients (4.1%) were classified as having surgical failures, requiring subsequent knee arthroplasty (n = 2) or a revision chondral procedure (n = 1). Mean visual analog scores improved significantly from 6.5 ± 1.5 to 3.2 ± 2.1 ( P < .0001). Multivariate analysis identified use of a periosteal patch as the only significant independent predictor for surgical ( P = .013) and overall ( P = .033) failures. Age <30 years ( P = .019), female sex ( P = .019), and regular tobacco use ( P = .011) were independent predictors of overall failure.

CONCLUSION

For patellofemoral chondral defects without a failed primary procedure, second-generation ACI successfully returned to work 78% of patients of moderate to very heavy occupational demand with significantly decreased patient-reported knee pain. Risk factors after ACI for patellofemoral articular lesions for overall failure were age <30 years, female sex, and tobacco use, while surgical and overall failures were associated with periosteal patch use.

The Effect of Tobacco Smoking on Musculoskeletal Health: A Systematic Review

This systematic review explored associations between smoking and health outcomes involving the musculoskeletal system. AMSTAR criteria were followed. A comprehensive search of PubMed, Web of Science, and Science Direct returned 243 articles meeting inclusion criteria. A majority of studies found smoking has negative effects on the musculoskeletal system. In research on bones, smoking was associated with lower BMD, increased fracture risk, periodontitis, alveolar bone loss, and dental implant failure. In research on joints, smoking was associated with increased joint disease activity, poor functional outcomes, and poor therapeutic response. There was also evidence of adverse effects on muscles, tendons, cartilage, and ligaments. There were few studies on the musculoskeletal health outcomes of secondhand smoke, smoking cessation, or other modes of smoking, such as waterpipes or electronic cigarettes. This review found evidence that suggests tobacco smoking has negative effects on the health outcomes of the musculoskeletal system. There is a need for further research to understand mechanisms of action for the effects of smoking on the musculoskeletal system and to increase awareness of healthcare providers and community members of the adverse effects of smoking on the musculoskeletal system.

Functional Medium-Term Results After Autologous Matrix-Induced Chondrogenesis for Osteochondral Lesions of the Talus: A 5-Year Prospective Cohort Study

Autologous matrix-induced chondrogenesis (AMIC) has gained popularity in the treatment of osteochondral lesions of the talus. Previous studies have presented promising short-term results for AMIC talar osteochondral lesion repair, a 1-step technique using a collagen type I/III bilayer matrix. The aim of the present study was to investigate the mid-term effects. The 5-year results of a prospective cohort study are presented. All patients underwent an open AMIC procedure for a talar osteochondral lesion. Data analysis included general demographic data, preoperative magnetic resonance imaging findings, intraoperative details, and German version of the Foot Function Index (FFI-D) scores preoperatively and at 1 and 5 years after surgery. The primary outcome variable was the longitudinal effect of the procedure, and the influence of various variables on the outcome was tested. Of 47 consecutive patients, 21 (45%) were included. Of the 21 patients, 8 were female (38%) and 13 were male (62%), with a mean age of 37 ± 15 (range 15 to 62) years and a body mass index of 26 ± 5 (range 20 to 38) kg/m². The defect size was 1.4 ± 0.9 (range 0.2 to 4.0) cm². The FFI-D decreased significantly from preoperatively to 1 year postoperatively (56 ± 18 versus 33 ± 25; p = .003), with a further, nonsignificant decrease between the 1- and 5-year follow-up examination (33 ± 25 versus 24 ± 21; p = .457). Similar results were found for the FFI-D subscales of function and pain. The body mass index and lesion size showed a positive correlation with the preoperative FFI-D overall and subscale scores. These results showed a significant improvement in pain and function after the AMIC procedure, with a significant return to sports by the 5-year follow-up point. The greatest improvement overall was seen within the first year; however, further clinical satisfaction among the patients was noticeable after 5 years.

A 20-Year Follow-up After First-Generation Autologous Chondrocyte Implantation

BACKGROUND

Treating articular cartilage defects is a demanding problem. Although several studies have reported durable and improved clinical outcomes after autologous chondrocyte implantation (ACI) over a long-term period, there is no report with over 20 years' follow-up.

PURPOSE

To evaluate clinical outcomes after first-generation ACI for the treatment of knees with disabling, large single and multiple cartilage defects for which patients wished to avoid prosthetic arthroplasty, with a minimum of 20 years' follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The authors reviewed prospectively collected data from 23 patients (24 knees; mean age, 35.4 years [range, 13-52 years]) undergoing ACI for the treatment of symptomatic, full-thickness articular cartilage lesions. A mean of 2.1 lesions per knee were treated over a mean total surface area of 11.8 cm² (range, 2.4-30.5 cm²) per knee. Kaplan-Meier survival analysis and functional outcome scores, including the modified Cincinnati Knee Rating System, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Short Form-36 (SF-36), were used. Patients also self-reported an improvement in pain with a visual analog scale and a satisfaction survey.

RESULTS

The 20-year survival rate was 63% (95% CI, 40%-78%). The evaluation of the 15 knees with retained grafts demonstrated that all clinical scores except the WOMAC subscore for stiffness and SF-36 mental component summary score improved significantly and were sustained to 20 years postoperatively. Ninety-three percent of these patients rated knee-specific outcomes as good or excellent. The outcomes for 9 of 24 knees were considered failures, including 5 undergoing revision ACI and 4 being converted to arthroplasty at a mean of 1.7 and 5.9 years, respectively. Only 1 of 5 knees that underwent revision ACI was converted to arthroplasty at 1.9 years after the index surgery, and the other 4 patients were able to maintain their biological knee. Overall, 20 years later, 79% of patients maintained their native knee, for which they initially sought treatment, and were satisfied when evaluated.

CONCLUSION

First-generation ACI provided satisfactory survival rates and significant clinical improvements over a 20-year follow-up, which offers an important standard for comparison with newer-generation ACI technologies of the future.

A Registry for Evaluation of Efficiency and Safety of Surgical Treatment of Cartilage Defects: The German Cartilage Registry (KnorpelRegister DGOU)

Background

The need for documentation in cartilage defects is as obvious as in other medical specialties. Cartilage defects can cause significant pain, and lead to reduced quality of life and loss of function of the affected joint. The risk of developing osteoarthritis is high. Therefore, the socioeconomic burden of cartilage defects should not be underestimated.

Objective

The objective of our study was to implement and maintain a registry of all patients undergoing surgical treatment of cartilage defects.

Methods

We designed this multicenter registry for adults whose cartilage defects of a knee, ankle, or hip joint are treated surgically. The registry consists of two parts: one for the physician and one for the patient. Data for both parts will be gathered at baseline and at 6-, 12-, 24-, 36-, 60-, and 120-month follow-ups.

Results

To date, a wide range of German, Swiss, and Austrian trial sites are taking part in the German Cartilage Registry, soon to be followed by further sites. More than 2124 (as of January 31, 2016) cases are already documented and the first publications have been released.

Conclusions

The German Cartilage Registry addresses fundamental issues regarding the current medical care situation of patients with cartilage defects of knee, ankle, and hip joints. In addition, the registry will help to identify various procedure-specific complications, along with putative advantages and disadvantages of different chondrocyte products. It provides an expanding large-scale, unselected, standardized database for cost and care research for further retrospective studies.

Trial Registration

German Clinical Trials Register: DRKS00005617; https://drks-neu.uniklinik-freiburg.de/ drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00005617 (Archived by WebCite at http://www.webcitation.org/6hbFqSws0)

Tobacco Use Is Associated With Increased Complications After Anterior Cruciate Ligament Reconstruction

BACKGROUND

The use of tobacco is a well-established cause of preventable morbidity and mortality. There have been few studies examining the effect of tobacco use on outcomes and complications after arthroscopic knee procedures such as anterior cruciate ligament (ACL) reconstruction.

PURPOSE

To investigate the relationship between tobacco use and rates of postoperative infection, venous thromboembolism (VTE), arthrofibrosis, and subsequent ACL reconstruction after primary ACL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A national insurance database was queried for patients who underwent arthroscopic-assisted ACL reconstruction using Current Procedural Terminology code 29888. Patients underage for tobacco use in all regions of the United States (age <20 years), those with prior ACL reconstruction, and those with the following concomitant procedures were excluded: open cruciate or collateral ligament reconstruction, open or arthroscopic cartilage procedures, patellar stabilization, extra-articular ligamentous reconstruction, and posterior cruciate ligament reconstruction. Tobacco use and non-tobacco use cohorts were queried using International Classification of Diseases-9th Revision coding. The non-tobacco use patients were then matched to the patients with coded tobacco use by age, sex, obesity, diabetes, meniscal repair, and meniscectomy. Complications within 90 days postoperatively were assessed for both cohorts, including infection, VTE, arthrofibrosis, and subsequent ipsilateral or contralateral ACL reconstruction after the index procedure.

RESULTS

A total of 13,358 patients who underwent ACL reconstruction met inclusion and exclusion criteria, including 1659 patients with documented tobacco use and 11,699 matched controls. The incidence of infection was significantly higher in patients who use tobacco (2.0%) versus matched controls (0.9%; odds ratio [OR], 2.3; P < .0001). The rate of VTE was also significantly higher in patients who use tobacco (1.0%) compared with matched controls (0.5%; OR, 1.9; P = .035). The rate of subsequent ACL reconstruction was significantly higher in the tobacco use cohort (12.6%) compared with matched controls (7.8%; OR, 1.7; P < .0001). There was no significant difference in the rate of postoperative stiffness after ACL reconstruction between patients who use tobacco (2.0%) and matched controls (2.3%; OR, 0.9; P = .656).

CONCLUSION

ACL reconstruction in patients who use tobacco is associated with significantly increased rates of infection, VTE, and subsequent ACL reconstruction compared with controls. There was no association between tobacco use and postoperative arthrofibrosis after primary ACL reconstruction.

Evaluation and analysis of graft hypertrophy by means of arthroscopy, biochemical MRI and osteochondral biopsies in a patient following autologous chondrocyte implantation for treatment of a full-thickness-cartilage defect of the knee

Graft hypertrophy represents a characteristic complication following autologous chondrocyte implantation (ACI) for treatment of cartilage defects. Although some epidemiological data suggest that incidence is associated with first-generation ACI using autologous chondrocyte implantation, it has also been reported in other technical modifications of ACI using different biomaterials. Nevertheless, it has not been described in autologous, non-periosteum, implant-free associated ACI. In addition, little is known about histological and T2-relaxation appearance of graft hypertrophy. The present case report provides a rare case of extensive graft hypertrophy following ACI using an autologous spheres technique with clinical progression over time. Detailed clinical, MR tomographic and histological evaluation has been performed, which demonstrates a high quality of repair tissue within the hypertrophic as well as non-hypertrophic transplanted areas of the repair tissue. No expression of collagen type X (a sign of chondrocyte hypertrophy), only slight changes of the subchondral bone and a nearly normal cell-matrix ratio suggest that tissue within the hypertrophic area does not significantly differ from intact and high-quality repair tissue and therefore seems not to cause graft hypertrophy. This is in contrast to the assumption that histological hypertrophy might cause or contribute to an overwhelming growth of the repair tissue within the transplantation site. Data presented in this manuscript might contribute to further explain the etiology of graft hypertrophy following ACI.

Clinical profiling in cartilage regeneration: prognostic factors for midterm results of matrix-assisted autologous chondrocyte transplantation

BACKGROUND

Matrix-assisted autologous chondrocyte transplantation (MACT) was developed to overcome the limitations of first-generation autologous chondrocyte implantation. Although short-term/midterm results are now available for a small series of patients, the literature still lacks studies on large cohorts of patients evaluated at midterm/long-term follow-up.

PURPOSE

Not all patients can have the same benefit from this procedure. The aim of this study is to analyze a large cohort of patients treated with hyaluronan-based MACT to perform clinical profiling and to highlight the patient- and lesion-specific aspects that play a key role in determining the prognosis.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 142 patients were treated for lesions involving the femoral condyles and trochleae; 133 knees were followed up yearly for 7 years. The average size of the defects was 2.3 ± 1.0 cm2. The origin was traumatic in 44 cases and degenerative in 57 cases, and 32 knees were affected by osteochondritis dissecans (OCD). The clinical outcome was analyzed using the International Knee Documentation Committee (IKDC), EuroQol visual analog scale, and Tegner scores. The influence of the following factors was analyzed: sex, age, body mass index, site, lesion origin, lesion size, previous or combined surgery, and symptom duration.

RESULTS

A marked improvement in all scores was found: the IKDC subjective score increased from the basal level of 39.6 ± 14.4 to 71.9 ± 19.8 (P < .0005) at 12 months; a further improvement was observed at 24 months (77.0 ± 20.5; P < .0005). The results were stable over time up to the 7-year evaluation (77.4 ± 22.1). The failure rate was 10.7%. Better results were seen in the trochleae, and among femoral condyles, the following factors were found to influence the clinical outcome positively: traumatic and OCD origin, male sex, short symptom duration (for traumatic lesions), small lesion size (for OCD), young age, and no previous surgery.

CONCLUSION

Treatment with MACT provides good and stable clinical results. Injury origin, sex, symptom duration, lesion size, lesion site, age, and previous surgery might determine the final outcome and can be used as a sort of clinical profiling to guide the surgeon in the choice of this procedure and in giving realistic expectations to patients requiring cartilage treatment.

Revision cartilage cell transplantation for failed autologous chondrocyte transplantation in chronic osteochondral defects of the knee

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.

Cigarette smoking and musculoskeletal disorders

Cigarette smoking has deleterious effects on the musculo-skeletal system. The loss of bone mineral content and increased incidence of fractures are the best known negative consequences. The pathogenesis is complex, due to direct toxic effects on osteoblasts/osteoclasts activity of nicotine, and indirect actions on sex and adrenocortical hormones, vitamin D, intestinal calcium absorption, vessels and oxygen supply. Smoking may favour the onset or aggravate the progression of rheumatoid arthritis and back pain. Negative influences have been observed on muscle and on tendons. Moreover, smoking habit is associated to a number of short term post-operative complications and higher resource consumption. Smoking cessation is highly advisable with positive effects on the bone metabolism on the long term. More positive and immediate results can be obtained in patients submitted to orthopedic surgery: the healing process is improved, the frequency of complications is reduced, and the length of hospital stay is shortened.

Factors predictive of outcome 5 years after matrix-induced autologous chondrocyte implantation in the tibiofemoral joint

BACKGROUND

Matrix-induced autologous chondrocyte implantation (MACI) has become an established technique for the repair of full-thickness chondral defects in the knee. However, little is known about what variables most contribute to postoperative clinical and graft outcomes as well as overall patient satisfaction with the surgery.

PURPOSE

To estimate the improvement in clinical and radiological outcomes and investigate the independent contribution of pertinent preoperative and postoperative patient, chondral defect, injury/surgery history, and rehabilitation factors to clinical and radiological outcomes, as well as patient satisfaction, 5 years after MACI.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This study was undertaken in 104 patients of an eligible 115 patients who were recruited with complete clinical and radiological follow-up at 5 years after MACI to the femoral or tibial condyles. After a review of the literature, a range of preoperative and postoperative variables that had demonstrated an association with postoperative clinical and graft outcomes was selected for investigation. These included age, sex, and body mass index; preoperative 36-item Short Form Health Survey (SF-36) mental component score (MCS) and physical component score (PCS); chondral defect size and location; duration of symptoms and prior surgeries; and postoperative time to full weightbearing gait. The sport and recreation (sport/rec) and knee-related quality of life (QOL) subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS) were used as the patient-reported clinical evaluation tools at 5 years, while high-resolution magnetic resonance imaging (MRI) was used to evaluate graft assessment. An MRI composite score was calculated based on the magnetic resonance observation of cartilage repair tissue score. A patient satisfaction questionnaire was completed by all patients at 5 years. Regression analysis was used to investigate the contribution of these pertinent variables to 5-year postoperative clinical, radiological, and patient satisfaction outcomes.

RESULTS

Preoperative MCS and PCS and duration of symptoms contributed significantly to the KOOS sport/rec score at 5 years, while no variables, apart from the baseline KOOS QOL score, contributed significantly to the KOOS QOL score at 5 years. Preoperative MCS, duration of symptoms, and graft size were statistically significant predictors of the MRI score at 5 years after surgery. An 8-week postoperative return to full weightbearing (vs 12 weeks) was the only variable significantly associated with an improved level of patient satisfaction at 5 years.

CONCLUSION

This study outlined factors such as preoperative SF-36 scores, duration of knee symptoms, graft size, and postoperative course of weightbearing rehabilitation as pertinent variables involved in 5-year clinical and radiological outcomes and overall satisfaction. This information may allow orthopaedic surgeons to better screen their patients as good candidates for MACI, while allowing treating therapists to better individualize their preoperative preparatory and postoperative rehabilitation regimens for a best possible outcome.

Comparing Responsiveness of Six Common Patient-Reported Outcomes to Changes Following Autologous Chondrocyte Implantation: A Systematic Review and Meta-Analysis of Prospective Studies

OBJECTIVE

To compare the responsiveness of six common patient-reported outcomes (PROs) following autologous chondrocyte implantation (ACI).

DESIGN

A systematic search was conducted to identify reports of PROs following ACI. Study quality was evaluated using the modified Coleman Methodology Score (mCMS). For each outcome score, pre- to postoperative paired Hedge's g effect sizes were calculated with 95% confidence intervals (CIs). Random effects meta-analyses were performed to provide a summary response for each PRO at time points (TP) I (<1 year), II (1 year to <2 years), III (2 years to <4 years), IV (≥4 years), and overall.

RESULTS

The mean mCMS for the 42 articles included was 50.9 ± 9.2. For all evaluated instruments, none of the mean effect size CIs encompassed zero. The International Knee Documentation Committee Subjective Knee Form (IKDC) had increasing responsiveness over time with TP-IV, demonstrating greater mean effect size [confidence interval] (1.78 [1.33, 2.24]) than TP-I (0.88 [0.69, 1.07]). The Knee Injury and Osteoarthritis Outcome Score-Sports and recreation subscale (KOOS-Sports) was more responsive at TP-III (1.76 [0.87, 2.64]) and TP-IV (0.98 [0.81, 1.15]) than TP-I (0.61 [0.44, 0.78]). Overall, the Medical Outcomes Study 36-Item Short Form Health Survey Physical Component Scale (0.60 [0.46, 0.74]) was least responsive. Both the Lysholm Scale (1.42 [1.14, 1.72]) and the IKDC (1.37 [1.13, 1.62]) appear more responsive than the KOOS-Sports (0.90 [0.73, 1.07]). All other KOOS subscales had overall effect sizes ranging from 0.90 (0.74, 1.22) (Symptoms) to 1.15 (0.76, 1.54) (Quality of Life).

CONCLUSIONS

All instruments were responsive to improvements in function following ACI. The Lysholm and IKDC were the most responsive instruments across time. IKDC and KOOS-Sports may be more responsive to long-term outcomes, especially among active individuals.

Repair of osteochondral defects in joints--how to achieve success

Osteochondral defects in the knee are difficult to repair because intrinsic healing of cartilage is poor and gradual progression to "early-onset" osteoarthritis leads to severe pain and disability. Of all methods tested to achieve regeneration of hyaline cartilage and long-lasting repair, autologous chondrocyte transplantation (ACI-C and MACI) has been the most successful with 80% of good results and graft survival in this unit in a very large series over 10 years. The repair mechanism is unclear but our work shows that the criteria for success are: young patient age, no previous operative procedures on the defect, no obesity, no smoking, defect on femoral condyles or trochlea and no pre-existing degenerative joint changes. Future research is aimed at non-transplantation, single-stage procedures aided by use of new scaffolds and growth factors and the extension of such techniques into arthritic joints.

The effect of smoking on ligament and cartilage surgery in the knee: a systematic review

BACKGROUND

The adverse effects of smoking on various health conditions such as cancer, diabetes, and cardiovascular disease have been well documented. Many orthopaedic conditions, such as fracture healing, wound repair, and bone mineral density, have been reported to be adversely affected by smoking. However, no known systematic reviews have investigated the effects of smoking on ligament and cartilage knee surgery.

PURPOSE

We hypothesized that smoking would have a negative influence from both a basic science and clinical outcome perspective on these types of knee surgeries.

STUDY DESIGN

Systematic review.

METHODS

A systematic review of multiple medical databases was performed evaluating clinical and basic science studies to determine the effects of smoking on ligament and cartilage knee surgery.

RESULTS

Fourteen studies were found for inclusion and analysis. Eight of these studies addressed the relationship between smoking and knee ligaments, and 6 investigated the relationship between smoking and articular cartilage. With the exception of 1, all of the basic science and clinical studies exploring the relationship between smoking and knee ligaments found a negative association of smoking, either molecularly, biomechanically, or clinically. One basic science and 3 clinical studies found a negative influence of smoking on articular cartilage of the knee. No studies were found that investigated the relationship of smoking and menisci.

CONCLUSION

The current literature reveals a negative influence of smoking on the results of knee ligament surgery, both from a basic science and clinical perspective, implying that smoking cessation would benefit patients undergoing these procedures. The association between smoking and knee articular cartilage was less clear, although the literature still suggests an overall negative influence and highlights the need for further investigation.

Nicotine-induced chondrogenic differentiation of human bone marrow stromal cells in vitro

PURPOSE

Nicotine has been reported that it has a dose-dependent effect on matrix mineralization by human bone marrow cells. However, there is no relevant research concerning on chondrogenic differentiation potential of bone marrow stromal stem cells (BMSCs) treated with nicotine in vitro. The aims of the study were to examine the effects of nicotine (0, 10(-7), 10(-6) and 10(-5) M) on the proliferation and chondrogenic differentiation of BMSCs from three healthy donors in vitro.

METHODS

BMSCs proliferation was analyzed by CCK8 assay and real-time polymerase chain reaction was used to assay the expression of type II collagen, aggrecan, type I collagen and type X collagen. The proteoglycan content was stained by Alcian blue, and the sulfated glycosaminoglycan (sGAG) content of BMSCs was quantified spectrofluorometrically using dimethylmethylene blue.

RESULTS

The cell viability was not significantly impaired until up to a concentration of 10(-5) M nicotine. Nicotine promoted the proliferation and enhanced the expression of type II collagen at the level up to 10(-6) M (P < 0.05). The expression of aggrecan was reduced at the concentration of 10(-5) M nicotine at day 14 (P < 0.05), and there was no significant difference in aggrecan gene expression at 10(-7) and 10(-6) M nicotine levels compared to control group (n.s.). Also the fibroblastic and hypertrophic gene expressions were down-regulated in the chondrogenic medium with 10(-7)-10(-5) M nicotine (P < 0.05).

CONCLUSION

It was implied that local application of nicotine at an appropriate concentration may be a promising approach for enhancing chondrogenic differentiation capacity of BMSCs in cell-based cartilage tissue engineering. Also these results indicate that nicotine maybe a potentially useful drug for the treatment of Osteoarthritis.

The musculoskeletal effects of perioperative smoking

Although the carcinogenic consequences of smoking are well known, further research is needed on the effects of smoking on musculoskeletal health and surgical outcomes. Orthopaedic perioperative complications of smoking include impaired healing, increased infection, delayed and/or impaired fracture union and arthrodesis, and inferior arthroplasty outcomes. The incorporation of smoking cessation protocols such as transdermal patches, chewing gum, lozenges, inhalers, sprays, bupropion, and varenicline in the perioperative period may result in substantial benefits for patients' musculoskeletal and general health.

Management of articular cartilage defects of the knee

Articular cartilage injuries of the knee present a difficult clinical dilemma and their treatment is controversial. Hyaline articular cartilage is an avascular, low-friction, and wear-resistant weightbearing surface that has limited capacity for self-repair. The optimal treatment for cartilage lesions has yet to be established. Various treatment methods are employed to reestablish a stable cartilage surface, including microfracture, autologous and allograft osteochondral transplantation, autologous chondrocyte implantation, matrix-associated chondrocyte implantation, and scaffold-assisted methods. Treatment algorithms help to guide physicians' decision making in the care of these injuries. In this article, results from outcomes studies as well as prospective randomized clinical trials comparing treatment methods are reviewed, and current practice guidelines are summarized.

Autologous chondrocyte implantation for treatment of cartilage defects of the knee: what predicts the need for reintervention?

BACKGROUND

Autologous chondrocyte implantation (ACI) is a well-established treatment option for isolated cartilage defects of the knee joint, providing satisfying outcome. However, cases of treatment failure with the need for surgical reintervention are reported; typical patient's individual and environmental risk factors have previously not been described.

HYPOTHESIS

The need for reintervention after ACI is associated with specific preoperative detectable individual risk factors.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 413 patients following ACI (first, second, and third generation) were filtered for those who required revision surgery during their follow-up time (2-11.8 years). Factors were analyzed that might have significant effects on increased revision rate. Using preoperatively collected data, all patients were grouped according to 12 standard prognostic factors. Apart from odds ratio and Pearson χ(2) test, statistical analysis of risk factors was performed with multivariate binary logistic regression models and Cox regression, the method of choice for survival time data.

RESULTS

After a follow-up of 4.4 ± 0.9 years (limited to 5 years), a total of 88 patients (21.3%) had undergone surgical revision. The time to revision surgery was 1.8 ± 1.1 years. Four prognostic factors associated with a significantly higher risk for reintervention were detected: (1) female gender (Cox survival fit: P = .033), (2) previous surgeries of the affected joint (P = .002), (3) previous bone marrow stimulation (P = .041), and (4) periosteum patch-covered ACI (P = .028). An influence of patient age, body mass index (BMI), defect number, defect size, lesion origin, lesion location, parallel treatment, or smoking on the risk for reintervention could not be observed.

CONCLUSION

The study identifies clear facts that significantly increase the risk of revision surgery. These facts can be easily obtained preoperatively and may be taken into consideration when indicating ACI.

Rehabilitation after autologous chondrocyte implantation for isolated cartilage defects of the knee

Autologous chondrocyte implantation for treatment of isolated cartilage defects of the knee has become well established. Although various publications report technical modifications, clinical results, and cell-related issues, little is known about appropriate and optimal rehabilitation after autologous chondrocyte implantation. This article reviews the literature on rehabilitation after autologous chondrocyte implantation and presents a rehabilitation protocol that has been developed considering the best available evidence and has been successfully used for several years in a large number of patients who underwent autologous chondrocyte implantation for cartilage defects of the knee.

Pain perception in knees with circumscribed cartilage lesions is associated with intra-articular IGF-1 expression

BACKGROUND

Circumscribed cartilage defects are considered as prearthritic lesions and lead to differential intra-articular cytokine expression. Mechanisms of associated pain development and influence of smoking behavior are not yet fully understood in humans.

PURPOSE

This study aimed to reveal relations between synovial cytokine levels in knees with circumscribed cartilage defects and pain sensation.

STUDY DESIGN

Descriptive laboratory study.

METHODS

In a clinical trial, knee lavage fluids of 42 patients with circumscribed cartilage lesions treated by either microfracturing (n = 19) or by autologous chondrocyte implantation (n = 23) and fluids of 5 healthy control individuals were prospectively collected. Preoperative knee pain was evaluated according to frequency and strength; subjective knee function was assessed using a visual analog scale and the International Knee Documentation Committee (IKDC) score. Synovial concentrations of aggrecan, insulin-like growth factor (IGF)-I, basic fibroblast growth factor (bFGF), interleukin (IL)-1β, bone morphogenetic protein (BMP)-2, and BMP-7 were determined by enzyme-linked immunosorbent assay.

RESULTS

Pain strength showed a highly significant association with intra-articular IGF-1 levels (ρ = .48, P < .01), but no correlation with synovial concentrations of aggrecan, bFGF, IL-1β, BMP-2, and BMP-7. Although pain strength and frequency demonstrated a statistically significant relationship, no substantial association between pain frequency and any of the examined cytokine levels was found. Intra-articular IGF-1 concentrations significantly correlated with the area of cartilage damage (ρ = .35, P < .02); the other investigated cytokines failed to show this association. Neither of the determined intra-articular mediators demonstrated statistically significant correlations with subjective knee function or IKDC score. Only intra-articular concentrations of IGF-1 and BMP-2 statistically significantly correlated with age; total protein content was negatively associated with body mass index (P < .05). In smokers, synovial expression of total protein content, IGF-1, and bFGF was significantly diminished compared to nonsmokers (P < .05).

CONCLUSION

Insulin-like growth factor-I is present in knees with circumscribed cartilage lesions in a size-dependent manner. IGF-1 levels correlated with indicators of pain perception; smoking negatively influenced synovial cytokine expression related to cartilage metabolism, but pain perception was not altered.

Nicotine promotes proliferation and collagen synthesis of chondrocytes isolated from normal human and osteoarthritis patients

The aims of the study were to show the direct effect of nicotine with different concentrations (0, 25, 50, and 100 ng/ml) on chondrocytes isolated from normal human and osteoarthritis patients, respectively. Microscopic observation was performed during the culture with an inverted microscope. Methyl thiazolyl tetrazolium (MTT) assay method was adopted to observe the influence of nicotine on the proliferation of chondrocytes, and real-time PCR and ELISA were used to assay the mRNA and protein expression of type II collagen and aggrecan, respectively. We discovered that the OA chondrocytes were similar to fibroblasts in shape and grow slower than normal chondrocytes. The proliferation of the two kinds of chondrocytes was increased in a concentration-dependent manner and in a time-dependent manner (P<0.05). Also, we found that the mRNA level of type II collagen were upregulated under 25-100 ng/ml nicotine doses both in the two kinds of chondrocytes compared with control. The expression of protein levels of type II collagen were synthesized in line with the increase in mRNA. No effect was observed on aggrecan synthesis with any nicotine dose. We concluded that nicotine has the same effect on both chondrocytes, obtained either from osteoarthritis patients or from normal human, and the positive effect of smoking in OA may relate to the alteration in metabolism of chondrocytes.

Stem cell therapy for articular cartilage defects

BACKGROUND

Stem cells are easily accessible and have great potential for healing articular cartilage defects. These features make stem cell therapy an appealing approach for treating severely impaired joint function.

SOURCES OF DATA

Clinical and basic research articles and literature reviews.

AREAS OF AGREEMENT

Stem cells possess the potential to build articular cartilage. Malalignment and instability corrections and proper rehabilitation are crucial prerequisites for surgical procedures involving stem cell therapy. Smoking reduces the result.

AREAS OF CONTROVERSY

Ethical concerns remain unresolved. No standards are established for inducing stem cell potential, optimizing culturing media or harvesting. The risk of failure has not been determined.

GROWING POINTS

Surgical scaffolds can improve results. Care givers should focus on re-educating patients. Improved funding is needed for developing the therapy.

AREAS TIMELY FOR DEVELOPING RESEARCH

Define guidelines for stem cell therapy and demonstrate effectiveness.

Cartilage repair: A review of Stanmore experience in the treatment of osteochondral defects in the knee with various surgical techniques

Articular cartilage damage in the young adult knee, if left untreated, it may proceed to degenerative osteoarthritis and is a serious cause of disability and loss of function. Surgical cartilage repair of an osteochondral defect can give the patient significant relief from symptoms and preserve the functional life of the joint. Several techniques including bone marrow stimulation, cartilage tissue based therapy, cartilage cell seeded therapies and osteotomies have been described in the literature with varying results. Established techniques rely mainly on the formation of fibro-cartilage, which has been shown to degenerate over time due to shear forces. The implantation of autologous cultured chondrocytes into an osteochondral defect, may replace damaged cartilage with hyaline or hyaline-like cartilage. This clinical review assesses current surgical techniques and makes recommendations on the most appropriate method of cartilage repair when managing symptomatic osteochondral defects of the knee. We also discuss the experience with the technique of autologous chondrocyte implantation at our institution over the past 11 years.