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

The role of autologous bone grafting in matrix-associated autologous chondrocyte implantation at the knee: Results from the German Cartilage Registry (KnorpelRegister DGOU)

PURPOSE

To investigate whether concomitant autologous bone grafting adversely affects clinical outcome and graft survival after matrix-associated autologous chondrocyte implantation (M-ACI).

METHODS

The present study examines registry data of patients who underwent M-ACI with or without autologous bone grafting for large-sized chondral or osteochondral defects. Propensity score matching was performed to exclude potential confounders. A total of 215 patients with similar baseline characteristics were identified. Clinical outcome was assessed at the time of surgery and at 6, 12, 24, 36 and 60 months using the Knee Injury and Osteoarthritis Outcome Score (KOOS). KOOS change, clinical response rate, KOOS subcomponents and failure rate were determined.

RESULTS

Patients treated with M-ACI and autologous bone grafting achieved comparable clinical outcomes compared with M-ACI alone. At 24 months postoperatively, the patient-reported outcome (PRO) of patients treated with M-ACI and autologous bone grafting was even significantly better as measured by KOOS (74.9 ± 18.8 vs. 79.2 ± 15.4; p = 0.043). However, the difference did not exceed the minimal clinically important difference (MCID). In patients with M-ACI and autologous bone grafting, a greater change in KOOS relative to baseline was observed at 6 (9.3 ± 14.7 vs. 15.0 ± 14.7; p = 0.004) and 12 months (12.6 ± 17.2 vs. 17.7 ± 14.6; p = 0.035). Overall, a high clinical response rate was observed in both groups at 24 months (75.8% vs. 82.0%; p = n.s.). The estimated survival at the endpoint of reoperation for any reason was 82.1% (SD 2.8) at 8.4 years for isolated M-ACI and 88.7% (SD 2.4) at 8.2 years for M-ACI with autologous bone grafting (p = 0.039).

CONCLUSIONS

Even in the challenging cohort of large osteochondral defects, the additional treatment with autologous bone grafting leads to remarkably good clinical outcomes in patients treated with M-ACI. In fact, they tend to benefit more from surgery, have lower revision rates and achieve clinical response rates earlier. Subchondral bone management is critical to the success of M-ACI and should be addressed in the treatment of borderline defects.

LEVEL OF EVIDENCE

Level III.

Operative management of osteochondral lesions of the talus: 2024 recommendations of the working group 'clinical tissue regeneration' of the German Society of Orthopedics and Traumatology (DGOU)

The working group 'Clinical Tissue Regeneration' of the German Society of Orthopedics and Traumatology (DGOU) issues this paper with updating its guidelines. Literature was analyzed regarding different topics relevant to osteochondral lesions of the talus (OLT) treatment. This process concluded with a statement for each topic reflecting the best scientific evidence available with a grade of recommendation. All group members rated the statements to identify possible gaps between literature and current clinical practice. Fixation of a vital bony fragment should be considered in large fragments. In children with open physis, retrograde drilling seems to work better than in adults, but even there, the revision rate reaches 50%. The literature supports debridement with bone marrow stimulation (BMS) in lesions smaller than 1.0 cm² without bony defect. The additional use of a scaffold can be recommended in lesions larger than 1.0 cm². For other scaffolds besides AMIC®/Chondro-Gide®, there is only limited evidence. Systematic reviews report good to excellent clinical results in 87% of the patients after osteochondral transplantation (OCT), but donor site morbidity is of concern, reaching 16.9%. There is no evidence of any additional benefit from autologous chondrocyte implantation (ACI). Minced cartilage lacks any supporting data. Metallic resurfacing of OLT can only be recommended as a second-line treatment. A medial malleolar osteotomy has a minor effect on the clinical outcome compared to the many other factors influencing the clinical result.

[The first decade of the DGOU's cartilage register-insights for clinical practice]

BACKGROUND

Registry data provide valuable epidemiological insights that help to further improve process and outcome quality in patient care. The German Cartilage Registry (KnorpelRegister DGOU) was established in 2013 as an instrument for quality assurance after surgical cartilage regenerative procedures on hip, knee and ankle joints.

DATA COLLECTION

Participation in the German Cartilage Registry is optional for hospitals and practices. Currently, more than 160 institutions in Germany, Austria and Switzerland participate in the data collection.

DATA COLLECTED AND INITIAL FINDINGS

The implementation of PROMs ("patient related outcome measurement"), as well as the recording of surgery-related influencing factors, enable a differentiated scientific analysis and represent a key quality feature of the registry. Initial analyses of the registry data have already provided clinically relevant findings for immediate patient care. For example, patients who underwent focal cartilage therapy prior to ACT show a clinically relevant, significantly worse outcome than patients who underwent primary ACT. First conclusions could also be drawn regarding the relevance of concomitant cartilage therapy. For example, in patients with focal cartilage damage of the medial knee joint compartment, registry data indicate that leg axis correction is indicated even in cases of mild deviation of the mechanical leg axis.

CONCLUSION

The data and findings obtained from the Cartilage Registry represent an important aspect of clinical care research and serve as a complement to well-designed, clinically prospective cohort studies, RCTs, and meta-analyses.

Descriptive analysis and short-term follow-up clinical results of osteochondral lesions of the distal tibia based on data of the German Cartilage Register (Knorpelregister® DGOU)

INTRODUCTION

An increasing number of ankle injuries with osteochondral lesions (OCL) also include lesions of the distal tibia. Therefore, the German Cartilage Society database is used to describe and examine the characteristics of these lesions and, early on, the results of different surgical therapies on the clinical outcome.

MATERIALS AND METHODS

Forty-seven patients out of 844 registered in the German Cartilage Society database met the inclusion criteria showing an OCL of the distal tibia (OLDT). Sixteen of them also presented a 1-year follow-up regarding the Foot and Ankle Ability Measure (FAAM). Further evaluations were included in the follow-up, such as the Foot and Ankle Outcome Score (FAOS) and the Visual Analogue Scale for pain (VAS).

RESULTS

The patients' mean age was 35 ± 11 with a mean BMI in the range of overweight (26/27 ± 5 kg/m²). The lesions were equally distributed on the articular surface of the distal tibia. Most patients were operated using anterior ankle arthroscopy [n_T 34 (72%); n_S 13 (81%)], while some (n_T 9; n_S 4) converted to open procedures. Almost 90% staged III and IV in the ICRS classification. Debridement, bone marrow stimulation, solid scaffolds, and liquid filler were the treatment choices among the subgroup. All therapies led to a clinical improvement between pre-op and 1-year follow-up but not to a significant level.

CONCLUSION

This study presents baseline data of OLDT based on data from a large database. BMS and scaffolds were the treatment of choice but did not present significant improvement after a 1-year follow-up.

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.

Effect of Previous Knee Surgery on Clinical Outcome After ACI for Knee Cartilage Defects: A Propensity Score-Matched Study Based on the German Cartilage Registry (KnorpelRegister DGOU)

BACKGROUND

Autologous chondrocyte implantation (ACI) is an established procedure for the treatment of cartilage damage in the knee joint. At present, it is still unclear how previous surgery influences outcome after ACI.

PURPOSE

To evaluate the effect of previous knee surgery related or nonrelated to the treated cartilage defect on clinical outcome after ACI for knee cartilage defects.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

An overall 730 patients with ACI who underwent previous unspecific knee surgery, whether related to the defect being currently treated or not, were identified from a cohort of 5961 patients registered in the German Cartilage Registry. Propensity score matching was used to match these patients to 690 patients with analogous characteristics but without previous surgery. Subsequently, 317 patients with previously failed cartilage treatment at the defect site were identified and compared with a matched collective of 254 patients without previous cartilage treatment. In a subgroup analysis, the type of previous cartilage surgery was additionally investigated. Outcome was evaluated by Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale for pain, rate of reintervention, and patient satisfaction up to 36 months. A chi-square test was used to compare categorial variables and an unpaired t test to compare continuous variables.

RESULTS

Patients with previous knee surgery not related to the cartilage defect showed a lower KOOS at 6 months (68.3 vs 70.8; P = .026), while patients with previous cartilage surgery showed significantly lower KOOS values at all follow-up time points when compared with patients without any previous knee or cartilage surgery (all P < .05). A comparison of KOOS values in patients with previous therapy at the cartilage defect with ACI versus bone marrow stimulation did not show any significant differences at any follow-up.

CONCLUSION

Previously failed cartilage treatment at the defect site represents a negative prognostic factor up to 3 years after ACI. However, this influence appears to be independent of the type of previous treatment at the defect site and applies equally to failed bone marrow stimulation as well as previous ACI. In contrast, a negative effect of previous surgery to the knee unrelated to the cartilage defect could not be shown in the 3-year follow-up.

Registry Studies Use Inconsistent Methods to Account for Patients Lost to Follow-up, and Rates of Patients LTFU Are High

PURPOSE

To determine methods described in the literature to account for patients lost to follow-up (LTFU) in registry studies and whether rates of patient LTFU are within acceptable margins.

METHODS

A scoping review, where a literature search is conducted for studies from 9 arthroscopy registries, was performed on EMBASE, MEDLINE, and the annual reports of each registry. Inclusion criteria included studies with information on patient-reported outcome measures and being based on 9 national registries identified. Exclusion criteria included review articles, conference abstracts, studies not based on registry data, and studies from regional, claims-based, or multicenter registries. Studies were then divided into categories based on method of LTFU analysis used.

RESULTS

Thirty-six articles were identified for the final analysis. Categories for LTFU analysis included dropout analyses (n = 10), referencing validation studies (n = 12), contacting nonresponders (n = 4), and sensitivity analyses (n = 1). Referencing validation studies was the most common method (n = 12). Majority (n = 35) of the studies exceeded the recommended maximum rates for LTFU.

CONCLUSIONS

Registry studies use inconsistent methods to account for patient LTFU, and rates of patients LTFU are unacceptably high.

CLINICAL RELEVANCE

The impact of patients LTFU in studies related to arthroscopic intervention is unknown. A universal method for accounting for patient follow-up is needed.

Parameters affecting baseline hip function in patients with cam-derived femoroacetabular impingement syndrome: data analysis from the German Cartilage Registry

BACKGROUND

Using the database of the German Cartilage Registry (KnorpelRegister DGOU), this study aims to present patient- and joint-related baseline data in a large cohort of patients with cam-derived femoroacetabular impingement syndrome (FAI) and to detect symptom-determining factors.

MATERIALS AND METHODS

Requiring cam morphology as the primary pathology, 362 patients were found to be eligible for inclusion in the study. The assessment of preoperative baseline data was performed using the patient-reported outcome measure-International Hip Outcome Tool (iHOT-33). Descriptive statistics were performed to present baseline data. Univariate and multiple regression with post hoc testing were used to identify patient- and joint-related factors that might affect the preoperative iHOT-33 and its subscores, respectively.

RESULTS

The study collective's mean age was 36.71 ± 10.89 years, with 246 (68%) of them being male. The preoperative mean iHOT-33 total was 46.31 ± 20.33 with the subsection "sports and recreational activities" presenting the strongest decline (26.49 ± 20.68). The parameters "age," "sex," "body mass index" (BMI), and the confirmation of "previous surgery on the affected hip" were identified to statistically affect the preoperative iHOT-33. In fact, a significantly lower mean baseline score was found in patients aged > 40 years (p < 0.001), female sex (p < 0.001), BMI ≥ 25 kg/m² (p = 0.002) and in patients with previous surgery on the affected hip (p = 0.022). In contrast, the parameters defect grade and size, labral tears, and symptom duration delivered no significant results.

CONCLUSIONS

A distinct reduction in the baseline iHOT-33, with mean total scores being more than halved, was revealed. The parameters "age > 40 years," "female sex," "BMI ≥ 25," and confirmation of "previous surgery on the affected hip" were detected as significantly associated with decreased preoperative iHOT-33 scores. These results help to identify symptom-defining baseline characteristics of cam-derived FAI syndrome.

TRIAL REGISTRATION

The German Cartilage Registry is conducted in accordance with the Declaration of Helsinki and registered at germanctr.de (DRKS00005617). Registered 3 January 2014-retrospectively registered. The registration of data was approved by the local ethics committees of every participating institution. Primary approval was given by the ethics committee at the University of Freiburg (No. 105/13). https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00005617.

Substantial Loss to Follow-Up and Missing Data in National Arthroscopy Registries: A Systematic Review

PURPOSE

To report follow-up methodologies, compliance, and existing strategies for handling missing data in national arthroscopy registries collecting patient-reported outcome measures (PROMs).

METHODS

Annual reports, EMBASE, and MEDLINE were queried following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines to identify national arthroscopy registries reporting follow-up with a validated PROM and sample size greater than 500. Extracted data included weighted compliance in peer-reviewed publications, cumulative compliance throughout the time span of data collection, and missing-data methodologies.

RESULTS

Nine national arthroscopy registries currently collect PROMs, with cumulative rates of follow-up ranging from less than 10% to more than 70%. We identified 36 publications from 5 national registries reporting hip and knee arthroscopies. The weighted mean compliance with PROMs in national registry publications was 56% at 0.5 years, 44% to 59% at 1 year, 40% to 61% at 2 years, 35% to 54% at 5 years, and 40% at 10 years. A missing-data analysis was reported or referenced in 58% of publications.

CONCLUSIONS

In national arthroscopy registries, compliance with 2-year PROMs does not meet traditional follow-up thresholds of 60% or 80% and reporting of missing-data methodologies is inconsistent.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II through IV studies.

Is debridement beneficial for focal cartilage defects of the knee: data from the German Cartilage Registry (KnorpelRegister DGOU)

INTRODUCTION

Focal cartilage defects of the knee are often treated with arthroscopic debridement. Existing literature discussing the benefit of debridement for small articular cartilage lesions is scarce, especially if the debridement was not part of a combined operative cartilage procedure including meniscal and ligament repair. The purpose of this study was to examine the patients´ benefit after arthroscopic debridement for the treatment of isolated focal chondral defects with or without partial meniscus resection.

MATERIALS AND METHODS

Baseline (preoperative data) and 12-month follow-up of the five Knee Osteoarthritis Outcome Score (KOOS) subscores and the Numeric Rating Scale (NRS) for pain were analyzed in 126 patients undergoing debridement for focal chondral defects of the knee from the German Cartilage Registry. Sub-analysis for patients receiving isolated debridement and debridement with concomitant partial resection of meniscal pathologies was performed. Thus, four subgroups were created according to the treated defect size and presence of meniscal pathologies: "debridement-only < 2 cm²", "debridement-only > 2 cm²", "debridement and partial meniscus resection < 2 cm²" and "debridement and partial meniscus resection > 2 cm²".

RESULTS

KOOS-subscores showed a significant increase from baseline to follow-up evaluation (p = 0.017-0.037) within the 126 patients. Sub-analysis showed significant improvement of all five KOOS-subscores in all three subgroups, except for the "debridement and partial meniscus resection > 2 cm²"-group: in this group the KOOS subscores symptoms and sports showed no significant improvement. The NRS scores revealed no significant changes from baseline to 12-month follow-up within the four subgroups.

CONCLUSION

An overall benefit of arthroscopic debridement for focal cartilage lesions of the knee could be conducted. Isolated cartilage defects seem to benefit from debridement irrespectively of size. In patients with large cartilage defects (> 2 cm²) and concurrent meniscal pathology expectation to improvement should be humbled. Effective reduction of pain by arthroscopic debridement remains unclear.

Revision Surgery After Cartilage Repair: Data From the German Cartilage Registry (KnorpelRegister DGOU)

Background:

Various operative strategies have been introduced to restore the integrity of articular cartilage when injured. The frequency of revision surgery after cartilage regenerative surgery remains incompletely understood.

Purpose/Hypothesis:

The purpose of this study was to identify the reasons for revision surgery after cartilage regenerative surgery of the knee. We hypothesized that in a large patient cohort, revision rates would differ from those in the current literature.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

A total of 2659 complete data sets from the German Cartilage Registry were available for analyses. In brief, baseline data were provided by the attending physician at the time of index surgery. Follow-up data were collected using a web-based questionnaire inquiring whether patients had needed revision surgery during follow-up, which was defined as the endpoint of the present analysis.

Results:

A total of 88 patients (3.3%) reported the need for revision surgery as early as 12 months postoperatively. Among the most common causes were arthrofibrosis (n = 27) and infection (n = 10). Female patients showed a significantly greater complication rate (4.5%) when compared with male patients (2.6%; P = .0071). The majority of cartilage lesions were located at the medial femoral condyle (40.2%), with a mean defect size of 3.5 ± 2.1 cm². Neither the location nor defect size appeared to lead to an increased revision rate, which was greatest after osteochondral autografts (5.2%) and autologous chondrocyte implantation (4.6%). Revision rates did not differ significantly among surgical techniques. Chi-square analysis revealed significant correlations between the number of previous joint surgeries and the need for revision surgery (P = .0203). Multivariate regression analysis further confirmed sex and the number of previous surgeries as variables predicting the need for early revision surgery.

Conclusion:

The low early revision rates found in this study underline that today’s cartilage repair surgeries are mostly safe. Although invasiveness and techniques differ greatly among the procedures, no differences in revision rates were observed. Specific factors such as sex and the number of previous surgeries seem to influence overall revision rates and were identified as relevant risk factors with regard to patient safety.

The German Arthroscopy Registry (DART)

In Germany, more than 400,000 arthroscopic procedures are performed each year. The DART registry is designed to study the outcome of arthroscopic procedures of the shoulder, hip, knee and ankle joint under everyday clinical circumstances using patient-reported outcome measures (PROMs). DART aims at identifying patient-specific factors correlated with therapy-associated complications and treatment failure and will help study the influence of concurrent joint diseases and procedures. To achieve these tasks, a Web-based remote data entry system will be applied and adapted to the needs of DART. DART will consist of a physician's and a patient's form to enter data on the specific disease, surgical procedure, joint-specific outcome, disability and quality of life measured by validated scores up to 5 years following surgery. The pool of data will be subjected to further clinical investigations and subgroup analysis. Individual results will be made accessible to the surgeon and the patient. Moreover, public reports will be generated to provide healthcare authorities and insurance companies with information on the effectiveness of arthroscopic surgery. The aim of this article is to present the methodology of the registry. Level of evidence V.

Development of a pilot cartilage surgery register

Background

Norway has no prospective surveillance system to monitor the outcome of knee cartilage surgery. In 2004 the Norwegian Registry of Knee Ligament (NKLR) was successfully established, and has yielded useful information on the treatment of patients with both knee ligament and combined knee injuries. Patients with focal cartilage defects (FCDs) in their knees have reduced function and the treatment is difficult. There are geographical variations in treatment, and the generalizability from randomized controlled studies is low. These patients would benefit from a standardized long-time follow-up through a cartilage surgery register.

The aim of the present study was to describe the development and report baseline challenges during the setting up of a pilot of a knee cartilage surgery register.

Methods

The study was designed as a prospective cohort study in the form of a register. Patients with full-thickness FCDs in the knee with International Cartilage Repair Society (ICRS) grade 3–4 on arthroscopy were included. The pilot included two hospitals; Oslo University Hospital (OUS), Ullevål and Akershus University Hospital (Ahus).

Results

We registered 58 patients with isolated FCDs, whereas 16 additional patients with full-thickness FCDs were registered through the NKLR. The patient cohort of patients with isolated FCDs consisted of 65% men and had a mean age of 29.8 years. The data are incomplete and the compliance varies from 18 to 73%. The distribution of mean KOOS scores were similar to previous patient cohorts with FCDs, with low scores for the KOOS Sport/Recreation and Quality of Life subscales.

Conclusion

The level of compliance demonstrated a large difference between the two participating hospitals. The compliance for the isolated FCDs were low in both locations, although it reached an acceptable level in one hospital when patients with combined injuries from the NKLR were included. The forms were incompletely filled out by the surgeons postoperatively and need to be revised prior the establishment of a nation-wide register.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1638-6) contains supplementary material, which is available to authorized users.