Purpose

Studies on knee cartilage lesions generally report controversial results comparing findings of men and women treated with regenerative procedures, although they are based on small patients’ number and short-term follow-ups. The aim of this study was to evaluate differences between sexes in long-term outcomes in patients affected by knee cartilage lesions treated with matrix-assisted autologous chondrocyte transplantation (MACT) technique.

Methods and Materials

A total of 217 patients (155 males and 62 females) were evaluated with the International Knee Documentation Committee (IKDC) subjective score at a minimum 10-year follow up after treatment with MACT for knee chondral lesions. The standardization of the IKDC scores was performed according to the mean score typical for the corresponding age/sex category in a healthy population. A further analysis was performed on a subgroup to compare more homogeneous patients.

Results

The mean follow-up was 14.0 ± 3.4 years (range 10-22 years). Women reported a statistically significant lower IKDC score than men (64.0 ± 23.3 vs 76.1 ± 20.5, respectively) (p<0.0005). The subgroup analysis did not confirm this difference (63.2 ± 23.2 vs 71.7 ± 22.0, respectively) (p>0.05). Finally, the score standardization confirmed the lack of differences between sexes in the total population (-1.8 ± 1.6 vs -1.5 ± 2.0, respectively) (p>0.05) as well as in the homogeneous group analysis (-1.9 ± 1.6 vs -1.7 ± 2.0, respectively) (p>0.05).

Conclusion

This analysis on patients with knee chondral lesions treated with MACT confirmed that women’s outcome was lower than men in the general population at long-term follow-up. However, when homogeneous populations were considered, also with standardized scores based on gender and sex, no differences between sexes were observed.

Purpose

Patient’s specific characteristics may play a role in determining clinical outcome after cartilage regenerative procedures. The objective of this analysis was to reveal if any correlation existed among patient’s characteristics and clinical outcome in the context of a RCT comparing an aragonite-based scaffold to debridement/microfractures for treating joint surface lesions.

Methods and Materials

A large RCT was performed in 26 medical centers, involving 167 subjects who underwent aragonite-based (Agili-C™, CartiHeal Ltd., Israel) scaffold implantation and 84 subjects who underwent arthroscopic debridement/microfractures (control) for the treatment of chondral/osteochondral knee defects. For each treatment group, the influence of age, sex, BMI, previous ligament reconstruction, pre-injury activity level and smoking history were analyzed to detect if a correlation existed in regards to the clinical outcome, up to the final evaluation at 24 months’ follow-up.

Results

Scaffold superiority over debridement/microfractures was confirmed across all sub-groups and covariates analysis. In the scaffold group, comparable clinical benefit was obtained in subjects younger or older than 50yy (p<0.0001). Moreover, the regenerative approach provided satisfactory outcome even in subjects older than 65yy, although their number in the present cohort was small. Differences between scaffold and control groups were much higher in females than in males, suggesting that the former, who usually present poorer prognosis after cartilage surgery, are good candidates for the aragonite-based implant. In the scaffold group, subjects with BMI lower or higher than 30 presented similar KOOS score improvement at 24 months, with better results than control even in obese patients. Previous ligament reconstruction and smoking history did not negatively influence the scaffold group. Considering pre-injury activity level, the comparison revealed particular advantage for the scaffold in non-active subjects.

Conclusion

The aragonite-based scaffold’s superiority over control was confirmed across all subgroups and covariates. Its efficacy was not influenced by sex, age, BMI, previous ligament surgery, smoking history and activity level.

Purpose

Autologous chondrocyte implantation (ACI) has been used to treat cartilage defects in the knee for over 25 years. It is successful at restoring function and alleviating pain in the short and mid-term, but there is limited longer-term data. We have examined follow-up data from patients treated in our centre over the past two decades, the aim being to investigate demographic, injury and surgery/treatment-associated factors that can influence clinical outcome (via Lysholm score), following ACI in a large, “real-world”, non-uniform, longitudinally collected clinical data set.

Methods and Materials

Multilevel (mixed) modelling was conducted using the programming language R. Of the 429 knee ACI procedures performed in our centre during the study period, 363 were suitable for model inclusion. All longitudinal post-operative Lysholm scores collected after ACI treatment and before a second procedure (such as knee arthroplasty but excluding minor procedures such as arthroscopy, debridement or biopsy for research) were included. Any patients requiring a bone graft at the time of ACI were also excluded. Potential predictors of ACI outcome explored in the model were age at the time of ACI, gender, smoker status, pre-operative Lysholm score, time from surgery, defect location, number of defects, patch type, previous operations, undergoing parallel procedure(s) at the time of ACI, cell count prior to implantation and cell passage number.

Results

Pre-operative Lysholm score, time from surgery, age at the time of ACI, defect location and undergoing a parallel procedure at the time of ACI were found to influence Lysholm scores post-ACI (but prior to a further surgical procedure).

Conclusion

We have developed a multilevel (mixed) model using a large database of non-uniform, longitudinally collected, longer-term ACI outcome data. The predictors identified agree with some of the previous findings reported from our centre (and others) based on smaller short and mid-term follow-up cohort studies, supporting this model as useful to other centres and patient cohorts.

Purpose

The purpose of this study was to (1) identify risk factors associated with early election to proceed with subsequent cartilage transplantation after a staging chondroplasty within 6 months and (2) develop a risk calculator with pre-operative prognostic value for conversion.

Methods and Materials

A retrospective review of patients prospectively enrolled at the time of staging chondroplasty was performed, with early election defined as patient decision to proceed to cartilage transplantation within six months of chondroplasty. Cox proportional hazards analysis was used to determine univariate predictors of conversion, and a predictive calculator was formulated using stepwise regression employing the Akaike Information Criterion (AIC). Postoperative patient-reported outcomes were compared between failure and non-failure cohorts in the timepoints leading up to the mean decision time to validate that failure correlated with worse PROMs.

Results

Sixty-five patients (67 knees) were included for analysis, with an overall election rate of 29.9% within six months after chondroplasty. Based on multivariate results, the final AIC-driven CERT score employed preoperative KOOS Pain Score, VR12 Physical Score, condylar involvement, and AMADEUS score to generate 0–7-point risk stratification system with a 3% early election to proceed to transplant risk in the 0–2-point score group, 33% risk in the 3–4-point group, and 79% risk in the 5+ point group (p < 0.01) and an overall AUC of 0.906 (p<0.01). By 6 weeks, early electing patients demonstrated significantly worse pain (61.71±17.97 vs 77.03±14.79, p=.003), daily living (84.75±14.26 vs 67.55±20.69, p=.002), sports (57.36±22.94 vs 32.14±28.67, p=.002), and quality of life scores (49.31±21.27 vs 22.33±20.33, p=<.001).

Conclusion

The risk of a given patient electing to proceed with a cartilage restoration procedure within 6 months after failing to derive therapeutic benefit from staging chondroplasty is closely and additively associated with pre-operative KOOS Pain Score, VR12 Physical Score, anatomic area involved, and lesion AMADEUS score. 

Purpose

Autologous chondrocyte implantation (ACI) is an effective treatment for isolated knee chondral defects. Increasing evidence highlights the impact of socioeconomic deprivation on the outcome of orthopaedic surgery. This study aimed to determine the association between socioeconomic deprivation and short-term patient-reported ACI outcomes.

Methods and Materials

All patients at our institution who underwent knee ACI between 1996-2020 were identified. Socioeconomic deprivation of their residential area was quantified by the Index of Multiple Deprivation (IMD) and employment/income deprivation. One-year Lysholm scores were the primary outcome. After transformation where needed to ensure normal distributions, linear multivariable regression was used to analyse the relation between IMD and 1-year Lysholm score, adjusting for demographic characteristics (age, sex, BMI and smoking) and baseline Lysholm.

Results

We identified 391 patients with mean age 50 years (range 16-84; 266 (68%) male). BMI and deprivation were log-transformed to achieve normal distributions. Median BMI was 27 (17-47): 138 patients (43%) were overweight and 105 (33%) obese. Seventy-seven patients lived in upper and 41 in lower quintile deprivation areas. The mean baseline Lysholm score was 49.8±17.3SD, improving to 66.5±21.3SD at 1 year. Mean one-year Lysholm scores were significantly lower with increasing area deprivation scores, adjusted for demographic factors (Table 1). Specifically, areas with high unemployment levels were associated with poorer functional outcomes (Table 1). Being female or having a lower baseline Lysholm was also associated with poorer outcomes, but age, BMI, smoking or higher income deprivation were not.

Conclusion

This study demonstrates poorer functional outcomes following ACI in patients from more deprived areas. Specifically higher unemployment levels were associated with lower mean 1-year Lysholm scores, as were female gender. Future studies in patients undergoing ACI should consider neighbourhood deprivation as a confounding factor. Further, targeting patients from areas with higher deprivation with special interventions may improve their outcomes.

Purpose

In a propensity score matched pair analysis using data from two phase III studies, M-ACI with an in-situ cross-linking hydrogel as chondrocyte carrier (NOVOCART® Inject plus) was compared to MFx in patients with focal knee cartilage defects.

Methods and Materials

The propensity score was estimated using the preoperative KOOS, duration of symptoms, previous knee surgeries, age and sex using a logistic regression model, resulting in 144 patients in the matched pair set (72 per group). The primary endpoint was the change in total KOOS from baseline to the 24-month assessment.

Results

Both groups were comparable regarding baseline KOOS, gender, age, body-mass index, duration of symptoms, smoking status and previous knee surgeries. Individual defect sizes in the M-ACI group were significantly larger than in the MFx group (4.8 cm² vs. 3.4 cm²). Further differences concerned defect location (no patellar or tibial defects in MFx), number of defects (M-ACI group: 33.3 % with two defects vs. MFx: 9.7%) and defect etiology (more patients with degenerative lesions in the M-ACI group). Both the absolute KOOS ​​and the KOOS changes from baseline at 24 months were higher in the M-ACI group (absolute KOOS: M-ACI 81.8 ± 16.8 vs. MFx 73.0 ± 20.6, KOOS change: M-ACI 40.1 ± 19.5 vs. MFx 30.6 ± 26.1). Treatment contrasts indicated statistically significant superiority of M-ACI from Month 3 up to Month 24 (p = 0.0026). Significant and clinically meaningful differences in favor of M-ACI at 24 months were also found for IKDC changes from baseline (37.8 points vs. 30.4 points, p = 0.0334), KOOS (94.4% vs. 65.3%, p <0.0001) and IKDC responder rates (83.3% vs. 61.1%, p = 0.0126).

Conclusion

In this explorative analysis, M-ACI with NOVOCART® Inject plus has demonstrated superior clinical outcomes compared to MFx in patients with knee cartilage defects during the 2-years follow-up.

Purpose

Background/Purpose: The goal of this study was to compare radiographic and patient reported outcomes at a minimum of two-years post matrix-induced chondrocyte implantation (MACI) between standard intercondylar region biopsy and osteochondral loose body biopsy.

Methods and Materials

Methods: A retrospective study was performed on all pediatric ACI procedures from 2014 to 2017 at a single institution. Patients were split into two groups: one group had cartilage derived from a standard intercondylar biopsy (n=9), and the other group had cartilage derived from osteochondral loose bodies found withing the ipsilateral knee (n=10). At a minimum one-year post-implantation, MRIs of the operative knee were performed and three individual orthopaedic surgeons used the MOCART 2.0 knee score to assess the cartilage. Interclass correlation coefficients (ICC) were calculated between the two groups. International Knee Documentation Committee (IKDC) scores were determined at a minimum two-years after implantation. Differences between outcomes were compared using a Wilcoxon rank-sum test.

Results

Results: The ICC between examiners for the MOCART scoring was excellent at 0.94. With regards to the MOCART score, the loose body group had an insignificant 17-point lower median score at 63 (IQR 59-89) compared to the intercondylar group at 80 (IQR 65-09) (p=0.151). With regards to the IKDC, the loose body group had an insignificant 2-point lower median score at 82 (IQR 65-95) compared to the intercondylar group at 84 (IQR 53-99) (p=0.902).

Conclusion

Conclusion: These results demonstrate that osteochondral loose bodies can be used as viable biopsies in MACI with no difference in functional and radiographic outcomes at two-years post-implantation. This may limit short and long term donor site morbidity.

Purpose

Proximal tibial osteotomy (PTO) is well-established for the treatment of coronal deformity and focal cartilage defects. However, the utility of joint preserving interventions must be weighed against potential effects on subsequent total knee arthroplasty (TKA). The purpose of this study was to determine the effect of PTO on subsequent TKA by robustly comparing outcomes in patients with bilateral TKAs following unilateral PTO.

Methods and Materials

Patients undergoing bilateral TKA between 2000–2015 at a single institution with previous unilateral valgus-producing PTO were reviewed. Knee Society Scores (KSS), Forgotten Joint Score 12 (FJS-12), subjective knee preference, and revision were compared between the PTO-TKA and contralateral TKA-only side.

Results

We evaluated 140 TKAs performed in 70 patients (24F, 46M) with unilateral PTO and subsequent bilateral TKA. Mean age at PTO was 50±8 years, with patients converting to TKA at a mean of 14±7 years following ipsilateral PTO and followed for a mean of 25±7 years (Range: 6–40).

PTOs demonstrated similar KSS (41±16) compared to their contralateral side (KSS: 39±16, p=0.67) immediately prior to arthroplasty. Patients had significant improvements in KSS (p<0.001) after TKA, with clinically similar KSS scores at 2–15 years of follow-up when comparing knees in a pairwise fashion (p>0.10). Five PTO-TKA knees (7%) and 4 control TKA-only knees (6%) underwent revision at a mean of 5 years postoperatively (p=0.76). A clinically relevant trend towards increased all-cause reoperation was observed in the PTO-TKA group (13% vs. 6%, p=0.24).

At final follow-up, PTO-TKA demonstrated similar FJS-12 scores (72±26) compared to the contralateral side (70±28, p=0.57). 19% of patients preferred their PTO-TKA knee, 19% preferred the contralateral knee, and 62% stated their knees were equivalent. Final Tegner activity score was 2.5±1.4.

Conclusion

Long-term clinical function of TKA following PTO is excellent, with comparable subjective outcomes and equivalent knee preference at 25 year follow-up compared to contralateral TKA-only knees.

Purpose

Systematic reviews have suggested that meniscal pathology, which occurs in up to 60% of patients with ACL injury, increases the risk of osteoarthritis following anterior cruciate ligament reconstruction (ACLR). The purpose of this study was to determine the incidence of osteoarthritis following lateral meniscus repair versus partial lateral meniscectomy in patients with ACLR.

Methods and Materials

All patients who underwent primary autograft or allograft bone-patellar tendon-bone (BPTB) transtibial ACLR by a single surgeon (1999-2018) were identified. Revision ACLR, multi-ligamentous reconstructions, and patients with less than 2-year imaging follow-up were excluded. Patients with lateral meniscus pathology at the time of ACLR were identified and treatment was extracted. Osteoarthritis was defined as Kellgren-Lawrence (KL) grade III-IV on plain radiographs at follow-up.

Results

A consecutive series of 107 patients (55 males, 52 females; age 35.9 ± 11.9 years) with BPTB ACLR were included (average follow-up 11.0 ± 5.1 [range 3-21 years]). The prevalence of lateral meniscus tears was 59.8% (64/107). 27.5% of patients (14/51) that underwent partial lateral meniscectomy developed lateral osteoarthritis compared to 0% of patients (0/13) that underwent lateral meniscal repair. Patients that underwent lateral meniscectomy had a 27.5% chance of developing lateral compartment knee osteoarthritis; a 6.2 times greater risk compared to patients that underwent lateral meniscus repair. Tear morphology, tear location, and tear zone were not found to be associated with the development of lateral osteoarthritis.

Conclusion

Following lateral meniscectomy, patients with lateral meniscal tears have an approximately 30% chance of developing grade 3-4 symptomatic osteoarthritis in the lateral compartment at 11-year follow-up. In contradistinction, successful lateral meniscus repairs substantially decrease the risk of developing osteoarthritis in the lateral compartment. We believe lateral meniscal repair is essential for lateral meniscus tears at the time ACL reconstruction to help avoid osteoarthritis development.