Chondromalacia patellae: assessment with MR imaging

Adults Have a Higher Incidence of Discoid Lateral Meniscus Tears Than Children-Adults Tend to Present With Complex Tears, While Horizontal Tear Patterns are Frequently Encountered in Children: A Systematic Review

PURPOSE

To systematically review the available literature in patients with discoid lateral meniscus (DLM) with the goal of elucidating the rates and types of meniscal tears, clinical symptoms, treatment strategies, and postoperative clinical, and radiographic outcomes in adult patients compared with a pediatric population.

METHODS

A literature search was performed using the PubMed, Embase, and Scopus databases from database inception to October 2023 according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Level of evidence I through IV human clinical studies evaluating rate and type of meniscal tears, clinical symptoms, patient-reported outcome measures, and postoperative radiographical assessments in patients with DLM were included. Comparisons were made by age below and above 16 years. Study quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS) criteria.

RESULTS

Thirteen studies comprising of 1772 adult patients (>16 years old) with DLM (n=1856 knees) and eight studies conducted in 304 pediatric patients (≤16 years old, n=353 knees) were include. The reported mean age ranged from 22.4 to 45 years (mean follow-up, 24 to 157.5 months) in the adult group and from 5 to 12.9 years (mean follow-up,37 to 234 months) in the pediatric DLM group. The majority of adult (n=553; 96.5%) and pediatric (n=163; 71.8%) patients had tears of the DLM. Complete DLM was the predominant type of DLM in both study groups (range in adults, 49.6 to 88%; range in pediatric, 19 to 100%) with complex (46.1%; range, 5.3-100%) and horizontal tears (18.2%; range, 20-37.5) being the most frequently described tear patterns in the adult and pediatric DLM groups, respectively. Pain was the predominant reported symptom in both study groups (range in adults, 12.1 to 99.3%; range in pediatrics, 32.4 to 100%). Partial meniscectomy was the most frequently reported treatment option conducted in 334 adult (39.5%; range, 24.2-100%) and 66 pediatric knees (63.5%; range, 15-100%).. Overall, improved postoperative clinical outcomes were reported in both study groups; however, radiographic progression of degenerative changes after subtotal meniscectomy was noted.

CONCLUSIONS

More adult patients with DLM present with tears in the literature compared with the pediatric population. Complex and horizontal tear patterns are the most frequently reported tears in adult and pediatric patients, respectively. . Pain is the most relevant symptom in both study groups. There was generally significant improvement in postoperative clinical outcome scores; partial meniscectomy however remains the most frequently reported treatment option and is associated with fewer degenerative changes than in subtotal meniscectomy. .

STUDY DESIGN

Level IV, Systematic review of Level I-IV studies.

Meniscal allograft transplantation in discoid meniscus patients achieves good clinical outcomes and superior chondroprotection compared to meniscectomy in the long term

PURPOSE

To compare the long-term clinical and radiological results of meniscal allograft transplantation (MAT) for discoid lateral meniscus (DLM) patients with MAT for non-discoid lateral meniscus patients and meniscectomy (ME) for DLM patients and, thus, to determine whether DLM patients are suitable candidates for MAT.

METHODS

Eight MAT cases in DLM patients were identified (discoid MAT group), six MAT cases in non-discoid lateral meniscus patients (non-discoid MAT group) and ten total meniscectomy cases in DLM patients (discoid ME group) were matched as controls. Subjective evaluations, postoperative radiography and magnetic resonance imaging (MRI) were conducted at 5 years and 10-14 years, respectively. Joint degeneration was evaluated by the Kellgren-Lawrance (KL) grade and joint space width (JSW). MRI with T2 mapping sequences was used to quantitatively evaluate degeneration of the joint cartilage and shrinkage of the allografts. Student's t test was used to compare quantitative variables and the Mann‒Whitney U test was used to compare categorical variables.

RESULTS

There was no difference in Lysholm, IKDC, Tegner or VAS scores amongst the discoid MAT, non-discoid MAT and discoid ME groups at the final follow-up. No revision surgery was performed in any MAT patient. The JSW narrowing in the discoid MAT group was better than that in the discoid ME group (0.8 ± 0.4 mm vs. 2.1 ± 1.3 mm, p = 0.012) and worse than that in the non-discoid MAT group (0.1 ± 0.1 mm, p = 0.003). The KL progression of the discoid MAT group was less than that of the discoid ME group (1.3 ± 0.7 vs. 2.3 ± 0.9, p = 0.034). The discoid ME group had worse cartilage lesion progression than the discoid MAT and non-discoid MAT groups. The allograft width of the DLM patients shrank more than that of the non-discoid patients at the meniscus midbody (3.6 ± 0.9 mm vs. 6.2 ± 1.9 mm, p = 0.015).

CONCLUSION

Compared to meniscectomy, MAT achieved similar long-term symptom relief and superior chondroprotection in discoid meniscus patients. Despite more graft shrinkage, the outcomes of MAT in discoid meniscus patients were comparable to those in non-discoid meniscus patients. Therefore, DLM patients may be suitable candidates for MAT procedures.

LEVEL OF EVIDENCE

Level III.

Hidden Unstable Flap Should Be Suspected in Treating Intractable Pain from Medial Meniscus Horizontal Tear

(1) Background: The medial meniscus horizontal tear (MMHT) is known as a lesion that can be treated nonoperatively. However, some patients show persistent pain despite conservative treatments. In arthroscopic surgery for MMHT, surgeons often encounter unexpected unstable flaps, which can explain the intractable pain. This study aimed to determine whether preoperative factors could predict the hidden unstable flaps in MMHT. (2) Materials and Methods: Medical records of 65 patients who underwent arthroscopic partial meniscectomy (APM) for isolated MMHT during 2016–2020 were retrospectively reviewed. APM was indicated when there was no severe chondral degeneration and intractable localized knee pain in the medial compartment did not resolve despite conservative treatments. Unstable flap was confirmed based on arthroscopic images and operation notes. Each of the following preoperative factors were investigated using logistic regression analyses to determine whether they can predict an unstable flap: age, sex, body mass index, lower limb alignment, trauma history, mechanical symptoms, symptom duration, visual analogue scale (VAS), Lysholm score, cartilage wear of the medial compartment, and subchondral bone marrow lesion (BML). (3) Results: Hidden unstable flaps were noted in 45 (69.2%) patients. Based on univariate analyses for each preoperative factor, age, symptom duration, cartilage wear (of the femoral condyle and the tibial plateau), and subchondral BML were included in the multivariate logistic regression analysis. The results showed that symptom duration (p = 0.026, odds ratio = 0.99) and high-grade cartilage wear of the medial femoral condyle (p = 0.017, odds ratio = 0.06) were negatively associated with unstable flaps. A receiver operating characteristic curve was used to calculate the symptom duration at which the prediction of unstable flaps was maximized, and the cutoff point was 14.0 months. (4) Conclusions: More than two thirds of patients suffering intractable pain from MMHT had hidden unstable flaps. However, APM should not be considered when the symptom duration is more than 14 months or high-grade cartilage wear of the medial femoral condyle is noted.

Magnetic resonance imaging is able to detect patellofemoral focal cartilage injuries: a systematic review with meta-analysis

PURPOSE

The purpose of this study was to analyze the diagnostic accuracy of magnetic resonance imaging (MRI) to detect and grade the severity of patellofemoral (PF) cartilage injuries.

METHODS

A systematic review was conducted on PubMed, EMBASE and Cochrane Library databases (up to July 1st 2022) to search for studies that reported the diagnostic accuracy of MRI to detect and grade PF cartilage injuries as compared to diagnostic arthroscopy. Risk of bias was judged using the QUADAS-2 tool. Quantitative syntheses were performed to calculate the diagnostic accuracy metric-sensitivity, specificity, positive likelihood (LR+) and negative likelihood (LR-) ratios, diagnostic odds ratio (DOR)-and presented as median with 25% and 75% percentiles. The summary receiver operating characteristic (SROC) curves were also calculated. Diagnostic accuracy metrics were calculated for all PF cartilage injuries and then sub-grouped by patellar and trochlear lesions. Diagnostic accuracy was also calculated according to the grading of cartilage injuries.

RESULTS

Forty-five studies were included for qualitative analyses and forty studies were included for quantitative synthesis. A total of 3534 participants with a weighted mean age of 38.1 years were included. Diagnostic accuracy was generally high: sensitivity (0.8, 0.6-1.0), specificity (0.9, 0.8-1.0), LR+ (6.4, 3.1-15.3), LR- (0.3, 0.2-0.4) and DOR (21.3, 9.9-121.1). The area under the curve (AUC) of the SROC was 0.9. The diagnostic accuracy was slightly higher for patellar (sensitivity 0.8, specificity 0.8, LR+ 5.3, LR- 0.2, DOR 28.8) than for trochlear lesions (sensitivity 0.7, specificity 0.9, LR+ 5.5, LR- 0.4, DOR 14.3). The sensitivity was generally higher when grading advanced (vs. early or intermediate) cartilage injuries of the patella.

CONCLUSION

The MRI is able to diagnose PF cartilage injuries with reasonably high diagnostic accuracy (as compared to arthroscopy). Clinicians can rely on MRI to reliably diagnose PF cartilage injuries (with some limitations) which will play an important role in deciding for surgical or non-operative treatment.

LEVEL OF EVIDENCE

Level III.

After Chondroplasty, Patient Election to Proceed With Cartilage Transplantation Is Closely and Additively Associated With Preoperative AMADEUS (Area Measurement And DEpth Underlying Structure) Grade, Condylar Involvement, Knee Injury and Osteoarthritis Outcome Score Pain Score, and Veterans Rand 12-Item Health Survey Physical Score

Purpose

To identify risk factors for patient election to proceed with cartilage transplant after staging chondroplasty.

Methods

This study retrospective reviewed patients prospectively enrolled at the time of staging chondroplasty, with early election defined as patient decision to proceed to cartilage transplantation within 6 months of chondroplasty. Cox proportional hazards analysis was used to determine univariate predictors of conversion, and a predictive calculator, the Cartilage Early Return for Transplant score, was formulated using stepwise regression employing the Akaike information criterion. Receiver operator curves and the area under the curve were used to evaluate the predictive ability of the final model on the studied patient population.

Results

Sixty-five knees (63 patients) were evaluated, with an overall transplant election rate of 27.7% within 6 months after chondroplasty. Based on multivariate results, the final Akaike information criterion-driven Cartilage Early Return for Transplant score employed preoperative Knee Injury and Osteoarthritis Outcome Score Pain Score, Veterans Rand 12-Item Health Survey Physical Score, condylar involvement, and AMADEUS (Area Measurement And DEpth Underlying Structure) score to generate a 0- to 7-point risk-stratification system with a 3% early election to proceed to transplant risk in the 0- to 2-point score group, 33% risk in the 3- to 4-point group, and 79% risk in the 5+-point group (P < .01) and an overall AUC of 0.906 (P < .01).

Conclusions

Risk of early patient election to pursue cartilage transplantation after chondroplasty is closely and additively associated with preoperative AMADEUS grade, condylar involvement, Knee Injury and Osteoarthritis Outcome Score Pain Score, and Veterans Rand 12-Item Health Survey Physical Score.

Clinical Relevance

Understanding risk factors for conversion to cartilage transplantation may improve preoperative planning and counseling prior to staging chondroplasty.

The Long-term Chondroprotective Effect of Meniscal Allograft Transplant: A 10- to 14-Year Follow-up Study

BACKGROUND

The long-term chondroprotective effect of meniscal allograft transplant (MAT) and its superiority over meniscectomy have rarely been reported.

HYPOTHESIS

MAT would reduce osteoarthritis (OA) progression when compared with the meniscus-deficient knee. Graft extrusion distance would strongly affect the chondroprotective effect of the MAT.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 17 knees receiving MAT were followed up as the MAT group. The MAT group was further divided into the nonextrusion subgroup (n = 9) and the extrusion subgroup (n = 8) according to 3-mm extrusion on the magnetic resonance imaging (MRI) coronal section. A further 26 consecutive patients receiving meniscectomy in the same period were followed up as the ME group. The healthy control group consisted of healthy contralateral legs chosen from the MAT and ME groups (n = 27). Joint space width (JSW) narrowing was measured on radiographs. Three-dimensional MRI with a T2 mapping sequence was used to quantitatively analyze cartilage degeneration and meniscal allograft extrusion in 5 directions (0°, 45°, 90°, 135°, and 180°). The cartilage degeneration index (CDI) was calculated according to the size and degree of the chondral lesions on MRI scans. The correlation between the CDI increase and the extrusion distance was analyzed.

RESULTS

The mean follow-up time was 11.3 years (range, 10-14 years). The MAT group had moderate superiority in chondral protection with less JSW narrowing (0.58 ± 0.66 mm) and CDI increase (1132 ± 1589) compared with the ME group (JSW narrowing: 1.26 ± 1.13 mm, P = .025; CDI increase: 2182 ± 1958, P = .079). The JSW narrowing (0.71 ± 0.80 mm; P = .186) and CDI increase (2004 ± 1965; P = .830) of the extrusion subgroup were close to those of the ME group, demonstrating that a 3-mm extrusion led to complete loss of the meniscal chondroprotective effect. The nonextrusion group had significantly less JSW narrowing (0.48 ± 0.48 mm; P = .042) and CDI increase (358 ± 249; P = .011) than the ME group. The JSW narrowing of the healthy control group was 0.22 ± 0.27 mm. The cartilage T2 values of the extrusion subgroup were similar to those of the ME group, with more OA features, whereas the T2 values of the nonextrusion subgroup were closer to those of the healthy control group. The extrusion distance in the 90° direction (P = .002) and the follow-up time (P = .019) significantly affected the CDI increase in the multivariate regression model. The average extrusion distance in the 45°, 90°, and 135° directions better predicted chondroprotection compared with the other individual directions.

CONCLUSION

MAT had moderate advantages in chondroprotection compared with meniscectomy in the long term. Graft extrusion distance strongly affected the chondroprotective effect of MAT. The chondroprotective effect of the nonextruded meniscal allograft was close to that of the native meniscus, whereas the allografts with an extrusion >3 mm completely lost their function after meniscectomy.

Knee Cartilage Imaging

Articular cartilage injury and degeneration represent common causes of knee pain, which can be evaluated accurately and noninvasively using MRI. This review describes the structure of cartilage focusing on its histologic appearance to emphasize that structure will dictate patterns of tissue failure as well as MR appearance. In addition to identifying cartilage loss, MRI can demonstrate signal changes that correspond to intrinsic structural abnormalities which place the cartilage at risk for subsequent more serious injury or premature degeneration, allowing for earlier intervention and treatment of important causes of pain and morbidity.

Minimum 10-Year Clinical Outcome of Lateral Collagen Meniscal Implants for the Replacement of Partial Lateral Meniscal Defects: Further Results From a Prospective Multicenter Study

Background:

The collagen meniscal implant (CMI) is a biologic scaffold aimed at replacing partial meniscal defects. The long-term results of lateral meniscal replacement have never been investigated.

Purpose:

To document the clinical outcomes and failures of lateral CMI implantation for partial lateral meniscal defect at a minimum 10-year follow-up.

Study Design:

Case series; Level of evidence, 4,

Methods:

This study included 24 consecutive patients who underwent lateral CMI implantation for partial lateral meniscal defects between April 2006 and September 2009 and who were part of a previous study with a 2-year follow-up. Outcome measures at the latest follow-up included the Lysholm score, Knee injury and Osteoarthritis Outcome Score, visual analog scale (VAS) for pain, Tegner activity level, and EuroQol 5-Dimensions score. Data regarding complications and failures were collected, and patients were asked about their satisfaction with the procedure.

Results:

Included in the final analysis were 19 patients (16 male, 3 female) with a mean age at surgery of 37.1 ± 12.6 years and a mean follow-up of 12.4 ± 1.5 years (range, 10-14 years). Five failures (26%) were reported: 1 CMI removal because of implant breakage and 4 joint replacements (2 unicompartmental knee arthroplasties and 2 total knee arthroplasties). The implant survival rate was 96% at 2 years, 85% at 5 years, 85% at 10 years, 77% at 12 years, and 64% at 14 years. Lysholm scores at the final follow-up were rated as “excellent” in 36% (5 of 14 nonfailures), “good” in 43% (6 of 14), and “fair” in 21% (3 of 14). The VAS score was 3.1 ± 3.1, with only 16% (3 of 19 patients) reporting that they were pain-free; the median Tegner score was 3 (interquartile range, 2-5). All clinical scores decreased from the 2-year follow-up; however, with the exception of the Tegner score, they remained significantly higher compared with the preoperative status. Overall, 79% of patients were willing to undergo the same procedure.

Conclusion:

Lateral CMI implantation for partial lateral meniscal defects provided good long-term results, with a 10-year survival rate of 85% and a 14-year survival rate of 64%. At the final follow-up, 58% of the patients had “good” or “excellent” Lysholm scores. However, there was a general decrease in outcome scores between the short- and the long-term follow-up.

Satisfactory clinical results and low failure rate of medial collagen meniscus implant (CMI) at a minimum 20 years of follow-up

PURPOSE

The aim of the study was to evaluate the long-term clinical results, reoperations, surgical failure and complications at a minimum of 20 year of follow-up of the first 8 medial CMI scaffolds implanted by a single surgeon during a pilot European Prospective study.

METHODS

Seven (88%) out of 8 patients were contacted. The Cincinnati Score, VAS, and Lysholm score were collected. Moreover, magnetic resonance imaging (MRI) was performed on 4 patients at the last follow-up. Complications, reoperations and failures were also investigated.

RESULTS

The average follow-up was 21.5 ± 0.5 years. One patient underwent TKA after 13 years from CMI implantation; a second patient underwent valgus high tibial osteotomy 8 years after the index surgery and another patient underwent anterior cruciate ligament hardware removal at 21 years of follow-up. At the final follow-up, 3 patients were rated as "Excellent", 1 as "Good" and 2 as "Fair" according to the Lysholm score. The Cincinnati score and the VAS were substantially stable over time. The MRI showed a mild osteoarthritis progression in 3 out of 4 patients according to the Yulish score, and the CMI signal was similar to the mid-term follow-up revealing 3 cases of myxoid degeneration and 1 case of normal signal with reduced scaffold size.

CONCLUSION

The medial CMI is a safe procedure: satisfactory clinical results and a low failure rate could be expected even at a long-term follow-up. For this purpose, the correct indication as well as correcting axial malalignment and addressing knee instability at the time of the index surgery is mandatory. On the other hand, a mild osteoarthritis progression could be expected even after meniscus replacement.

LEVEL OF EVIDENCE

IV.

A professional athlete functionally active 10 years after an arthroscopic lateral collagen meniscus implant

The case of a former high-level professional soccer player is presented at 10-year follow-up after arthroscopically implanted lateral Collagen Meniscus Implant (CMI). The patient achieved a full-knee functional recovery and a complete sport resumption to the same pre-injury level for several soccer seasons and he is still performing semi-professional soccer activity (minor league) 10 years after surgery.Level of evidence Case Report. Level IV.

Microstructural analysis of subchondral bone in knee osteoarthritis

The results of this study show increased formation of bone in the subchondral areas in advanced stages of osteoarthritis of the knee. These changes seem to be influenced by mechanical factors.

INTRODUCTION

Subchondral bone changes seem to contribute to the progression of knee osteoarthritis (OA). This study aimed to analyze subchondral bone microstructure in specimens of late-stage knee OA in respect to articular cartilage damage, meniscus integrity, and knee joint alignment.

METHODS

Thirty proximal tibiae of 30 patients (20 female and 10 male) with late-stage OA retrieved during total knee arthroplasty were scanned using a high-resolution micro-computed tomography. The scans were semi-automatically segmented into five volumes of interest. The volumes of interest were then further analyzed using commercially available software. The degree of articular cartilage damage was assessed semi-quantitatively by magnetic resonance imaging before surgery.

RESULTS

The mean bone fraction volume (bone volume/total volume (BV/TV)) in all weight-bearing locations was significantly higher compared to the non-weight-bearing reference point below the anterior cruciate ligament (p = 0.000). The mean BV/TV in the medial compartment was significantly higher compared to the lateral compartment (p = 0.007). As for the BV/TV in intact menisci, there was a significantly lower subchondral bone fraction volume compared to subluxated or luxated menisci in the medial (p = 0.020) and lateral compartment (p = 0.005). Varus alignment had a significantly higher subchondral BV/TV in the medial compartment, whereas valgus alignment had a significantly higher subchondral BV/TV in the lateral compartment (p = 0.011).

CONCLUSIONS

The results show significant differences of subchondral bone microstructural parameters in respect to cartilage damage, meniscus' structural integrity, and knee joint alignment. Therefore, subchondral bone changes seem to be a secondary process in the late-stage OA of the knee caused by mechanical changes.

Meniscus sutures by arthrotomy for a non-transfixing horizontal lesion associated with a cyst

INTRODUCTION

Meniscal cysts are rare in Stoller grade II horizontal lesions. Several techniques are described in the literature for their management, without any real gold standard. The objective of this work was to report a series of meniscal sutures associated with cyst resection by arthrotomy. The hypothesis was that the results were satisfactory and comparable with the data in the literature regardless of the technique reported without morbidity added by arthrotomy.

MATERIALS AND METHODS

This was a monocentric retrospective study on 13 patients, aged 33 on average with a grade II meniscus lesion associated with a cyst (9 lateral and 4 medial menisci). Pre-operative data available was the VAS (5.7/10) and the Lysholm score (61/100). Primary endpoints were as follows: pain (visual analogue scale), global satisfaction, Lysholm functional score, and return to sports and professional activities at a minimum of two years. Secondary endpoints were complications, possible recurrence, and/or surgical revision. Recurrences, complications, and surgical recovery were gathered.

RESULTS

Patients were evaluated with an average follow-up of 32 months. All patients were satisfied or very satisfied. The VAS significantly improved (0.2/10, p < 0.05) as well as the Lysholm score (97/100, p < 0.05). All patients returned to their professional activity: 11 within two months, one within six weeks, and one in the first post-operative week (this patient being a student). Only one patient did not resume pre-operative sport level due to a femoropatellar syndrome, not linked to the meniscal surgery performed. However, only 11 patients resumed their previous sport level (84.6%). No recurrence or surgical revision occurred.

DISCUSSION

The results are good and similar to the literature, confirming the working hypothesis. These results are equivalent to partial meniscectomies and arthroscopic sutures associated with a procedure on the cyst by arthroscopy or arthrotomy. The literature is in favour of a procedure on the cyst.

CONCLUSION

The results confirm the effectiveness of a direct approach suture of non-transfixing meniscal lesions associated with a cyst resection with a good functional recovery, without additional morbidity. The hypothesis was confirmed.

The biomechanical role of meniscal allograft transplantation and preliminary in-vivo kinematic evaluation

Background

Meniscus allograft transplantation (MAT) is a surgical procedure performed in patients complaining post-meniscectomy syndrome. Although the effectiveness of MAT on knee stability has been already demonstrated in cadaveric studies, its biomechanical role has been poorly evaluated in-vivo.

Methods

A narrative review of the biomechanical effect of meniscectomy and MAT was performed. Furthermore, two cases were presented, of one patient who underwent Medial MAT and Anterior Cruciate Ligament (ACL) reconstruction, and one who underwent Lateral MAT. During the surgery, knee laxity was evaluated using a surgical navigation system.

Results

AP laxity and IE rotation were reduced of 25% to 50% at both 30° and 90° of knee flexion after MAT transplantation.

Discussion

In both cases, almost all the tests performed showed a reduction of knee laxity after meniscus transplant, when compared with pre-operative knee laxity. This assessment confirms the insights of previous in-vitro studies and underline a crucial role of MAT in knee biomechanics.

Are the Biological and Biomechanical Properties of Meniscal Scaffolds Reflected in Clinical Practice? A Systematic Review of the Literature

The aim of this PRISMA review was to assess whether the CMI and Actifit scaffolds, when used in clinical practice, improve clinical outcomes and demonstrate the ideal biological and biomechanical properties of scaffolds: being chondroprotective, porous, resorbable, able to mature and promote regeneration of tissue. This was done by only including studies that assessed clinical outcome and used a scale to assess both integrity of the scaffold and its effects on articular cartilage via MRI. A search was performed on PubMed, EMBASE, Scopus and clinicaltrials.gov. 2457 articles were screened, from which eight studies were selected: four used Actifit, three used CMI and one compared the two. All studies reported significant improvement in at least one clinical outcome compared to baseline. Some studies suggested that the scaffolds appeared to show porosity, mature, resorb and/or have possible chondroprotective effects, as assessed by MRI. The evidence for clinical translation is limited by differences in study methodology and small sample sizes, but is promising in terms of improving clinical outcomes in the short to mid-term. Higher level evidence, with MRI and histological evaluation of the scaffold and articular cartilage, is now needed to further determine whether these scaffolds exhibit these useful properties.

Polyurethane meniscal scaffolds lead to better clinical outcomes but worse articular cartilage status and greater absolute meniscal extrusion

PURPOSE

Implantation of polyurethane (PU) meniscal scaffolds has become a popular procedure to provide a scaffold for vessel ingrowth and meniscal tissue regeneration in patients with partial meniscal defects. However, it is unclear whether PU meniscal scaffolds lead to better clinical and magnetic resonance imaging (MRI) outcomes post-operatively. This meta-analysis compared the clinical and MRI outcomes in patients with partial meniscal defects treated with PU meniscal scaffolds.

METHODS

This meta-analysis reviewed all studies that assessed Lysholm score, International Knee Documentation Committee (IKDC) score, visual analogue scale (VAS) for pain, Tegner score, Knee Injury and Osteoarthritis Outcomes Score (KOOS), articular cartilage (AC), absolute meniscal extrusion (AME), morphology and size (MS), signal intensity (SI) of meniscal implant, and interface of the implant-residual meniscus complex (IIRMC) in patients with partial meniscal defects treated with PU meniscal scaffolds.

RESULTS

Eighteen studies were included in the meta-analysis. The proportion of patients who evaluated MS (OR 0.71, 95% CI 0.38-1.33; n.s.), SI (OR 1.07, 95% CI 0.53-2.18; n.s.), and IIRMC (OR 1.00, 95% CI 0.33-3.06; n.s.) did not differ significantly between baseline and final follow-up. However, AC (OR 0.31, 95% CI 0.11-0.84; P = 0.02) and AME (OR 0.05, 95% CI 0.01-0.18; P < 0.00001) worsened between baseline and final follow-up. Conversely, Lysholm score (95% CI -1.87 to -1.07; P < 0.00001), IKDC score (95% CI -2.19 to -1.08; P < 0.00001), VAS for pain (95% CI -2.29 to -1.07; P < 0.00001), Tegner score (95% CI -0.76 to -0.15; P = 0.003), and overall KOOS (95% CI -29.48 to -23.17; P < 0.00001) were significantly greater at final follow-up when compared to baseline.

CONCLUSION

This meta-analysis found no significant differences in the tested MRI parameters, including MS, SI, and IIRMC. However, AC and AME worsened between baseline and final follow-up. Conversely, patients treated with PU meniscal scaffolds showed significant functional improvement and pain relief when compared with baseline scores. Thus, PU meniscal scaffolds appear to be a viable alternative for patients with partial meniscal defects, although further studies are needed to determine whether worsened AC and AME are clinically relevant. In particular, precise measurement of PU meniscal scaffolds in combination with thorough investigation of the baseline articular cartilage status and meniscal defect size may be effective for pain relief or functional improvement in patients with PU meniscal scaffold implantation.

LEVEL OF EVIDENCE

III.

Similar clinical outcomes following collagen or polyurethane meniscal scaffold implantation: a systematic review

PURPOSE

The purpose of this systematic review is to evaluate the current literature in an effort to assess specific clinical outcomes following meniscal scaffold implantation using the two available scaffolds: Collagen Meniscal Implant (CMI) and the Actifit polyurethane meniscal scaffold.

METHODS

A systematic review was performed by searching PubMed, Embase, and Cochrane Library to find studies evaluating clinical outcomes of patients undergoing meniscal scaffold implantation. Search terms used were "meniscus", "meniscal", "scaffold", and "implant". Studies were evaluated based on scaffold type, treatment failure rates, patient-reported outcome scores, concomitant procedures, and radiological findings. Radiological findings were recorded using the Genovese scale to assess morphology and signal intensity and the Yulish score to assess articular cartilage.

RESULTS

Nineteen studies (1 level I, 1 level II, 17 level IV evidence) were identified that met inclusion criteria, including a total of 658 patients (347 Actifit, 311 CMI). The overall average follow-up was 45 months. Treatment failure occurred in 9.9% of patients receiving the Actifit scaffold at a mean follow-up of 40 months and 6.7% of patients receiving CMI at a mean follow-up of 44 months (n.s.). However, the rate of failure ranged from 0 to 31.8% amongst the included studies with a variable definition of failure. Additionally, overlapping patients and presence of concomitant surgeries such as anterior cruciate ligament reconstruction (ACLR) and high tibial osteotomy (HTO) may have a significant influence on these results. Outcomes for the Visual Analog Scale (VAS) for pain, Lysholm knee score, and Tegner activity score improved from preoperatively to latest follow-up in both groups, while the Knee Injury and Osteoarthritis Outcome Score and International Knee Documentation Committee scores improved from preoperatively to latest follow-up for Actifit scaffold patients. Overall, patients receiving CMI scaffolds had higher grades for Genovese morphology and signal intensity when compared to Actifit scaffold patients.

CONCLUSION

Patients undergoing meniscal scaffold implantation with either CMI or Actifit scaffold can both be expected to experience improvement in clinical outcomes when used in association with concomitant procedures such as ACLR and HTO.

LEVEL OF EVIDENCE

IV, systematic review.

Arthroscopic partial meniscectomy in young patients with symptomatic discoid lateral meniscus: an average 10-year follow-up study

INTRODUCTION

The aim of this study is to evaluate mid-to-long-term clinical and radiological outcomes after an arthroscopic partial meniscectomy for symptomatic discoid lateral meniscus (DLM) in young patients and to determine whether degeneration of the residual meniscus and articular cartilage progresses during the follow-up period using magnetic resonance imaging (MRI).

MATERIALS AND METHODS

We retrospectively reviewed patients aged ≤ 40 years at surgery who underwent arthroscopic partial meniscectomy for symptomatic DLM and were followed up for ≥ 5 years. Lysholm knee scores and reoperation rates were assessed as clinical outcomes. Factors that affect clinical outcomes were evaluated. Tapper-Hoover classification and femorotibial angle were used for radiological assessment. The degree of degeneration of articular cartilages and residual meniscus was evaluated using preoperative and follow-up MRIs.

RESULTS

A total of 73 knees (66 patients) were enrolled. The mean follow-up period was 10.0 years. The mean follow-up Lysholm knee score was 84.2 ± 14.5, and the reoperation rate was 32.9%. Follow-up Lysholm knee scores were related to duration of symptoms prior to surgery (β = - 0.129, P = 0.003) and femorotibial angle at the last follow-up (β = 1.362, P = 0.045). On simple radiographs, progression of arthritis of the lateral compartment was observed in 68.5% (49 knees). In MRI analyses, degeneration of the residual meniscus progressed in 52.9% (34 knees) (P < 0.001), and significant changes in modified Yulish scores were observed in both lateral femoral and tibial condyles (P < 0.001, both condyles).

CONCLUSIONS

After an arthroscopic partial meniscectomy for symptomatic DLM, unfavorable clinical outcomes were shown in > 30% of the patients during a mean follow-up of 10.0 years. Clinical outcomes based on the patient-reported outcome measures were related to durations of symptoms prior to surgery and alignment at the last follow-up. In radiological and MRI assessments, progression of degeneration of articular cartilages in the lateral compartments of the knees and residual menisci was observed.

Magnetic Resonance Imaging Score and Classification System (AMADEUS) for Assessment of Preoperative Cartilage Defect Severity

Objective To design a simple magnetic resonance (MR)-based assessment system for quantification of osteochondral defect severity prior to cartilage repair surgery at the knee. Design The new scoring tool was supposed to include 3 different parameters: (1) cartilage defect size, (2) depth/morphology of the cartilage defect, and (3) subchondral bone quality, resulting in a specific 3-digit code. A clearly defined numeric score was developed, resulting in a final score of 0 to 100. Defect severity grades I through IV were defined. For intra- and interobserver agreement, defects were assessed by 2 independent readers on preoperative knee MR images of n = 44 subjects who subsequently received cartilage repair surgery. For statistical analyses, mean values ± standard deviation (SD), interclass correlation coefficients (ICC), and linear weighted kappa values were calculated. Results The mean total Area Measurement And DEpth & Underlying Structures (AMADEUS) score was 48 ± 24, (range, 0-85). The mean defect size was 2.8 ± 2.6 cm². There were 36 of 44 full-thickness defects. The subchondral bone showed defects in 21 of 44 cases. Kappa values for intraobserver reliability ranged between 0.82 and 0.94. Kappa values for interobserver reliability ranged between 0.38 and 0.85. Kappa values for AMADEUS grade were 0.75 and 0.67 for intra- and interobserver agreement, respectively. ICC scores for the AMADEUS total score were 0.97 and 0.96 for intra- and interobserver agreement, respectively. Conclusions The AMADEUS score and classification system allows reliable severity encoding, scoring and grading of osteochondral defects on knee MR images, which is easily clinically applicable in daily practice.

The Genovese grading scale is not reliable for MR assessment of collagen meniscus implants

BACKGROUND

The purpose of the study was to evaluate the intra- and inter-observer reliabilities of the Genovese grading on MRI in patients after collagen meniscus substitution.

METHODS

84 MRI images of 74 consecutive patients who underwent partial meniscus substitution using collagen meniscus implant (CMI) were assessed. MRIs were evaluated using the Genovese grading system. Furthermore, meniscal extrusion was assessed. Two observers performed the grading twice, blinded to each other and to the previous results, with a six weeks interval. The inter- and intra-observer reliabilities were assessed using kappa and weighted kappa values.

RESULTS

The criterion "morphology/size" showed a weighted kappa value inter-observer reliability of 0.069 (rater 1)/0.352 (rater 2) and intra-observer reliability of 0.170 (1st rating)/0.582 (2nd rating). The criterion "signal intensity" showed a weighted kappa value inter-observer reliability of 0.175/0.284 and intra-observer reliability of 0.294/0.458. The criterion "cartilage lesions" showed a kappa value inter-observer reliability of 0.091/0.525 and intra-observer reliability of 0.409/0.413. The criterion "bone marrow edema" showed a kappa value inter-observer reliability of 0.667/0.808 and intra-observer reliability of 0.702/0.715. The criterion "cartilage lesions" showed a kappa value inter-observer reliability of 0.091/0.525 and intra-observer reliability of 0.409/0.413. Regarding meniscal extrusion kappa values for the inter-observer reliability were 0.625/0.940 and 0.625/0.889 for intra-observer reliability.

CONCLUSIONS

Three of the four Genovese grading items showed only slight to moderate inter- and intra-observer reliabilities in evaluating CMI on MRI. Hence, such grading results need to be considered with all due care. Only the criteria "bone marrow edema" and "meniscal extrusion" showed a good agreement for both inter- and intra-observer reliabilities.

Is meniscal allograft transplantation chondroprotective? A systematic review of radiological outcomes

PURPOSE

The primary aim of this systematic review was to examine the hypothesis that meniscal allograft transplantation is chondroprotective by identifying and appraising studies that have assessed the progression of osteoarthritis following meniscal allograft transplantation. The secondary aim was to identify and appraise radiological measures of meniscal allograft integrity following surgery.

METHODS

Clinical studies on human participants undergoing meniscal allograft transplantation with a minimum follow-up of 6 months were included. The primary outcome measure was any radiological osteoarthritis progression measure. Secondary outcomes included magnetic resonance measures of meniscal integrity including meniscal size, shape, healing, extrusion and signal intensity.

RESULTS

Thirty-eight studies with 1056 allografts were included. The weighted mean joint space loss was 0.032 mm at 4.5 years across 11 studies. Other radiological classification systems were reported in small numbers and with variable progression rates. Meniscal extrusion was present in nearly all cases, but was not associated with clinical or other radiological outcomes. Meniscal healing rates were high, although the size, shape and signal intensity were commonly altered from that of the native meniscus. The quality of the included studies was low, with a high risk of bias.

CONCLUSION

There is some evidence to support the hypothesis that meniscal allograft transplantation reduces the progression of osteoarthritis, although it is unlikely to be as effective as the native meniscus. If this is proven, there may be a role for prophylactic meniscal allograft transplantation in selected patients. Well-designed randomised controlled trials are needed to further test this hypothesis.

LEVEL OF EVIDENCE

Systematic review of studies, Level IV.

MR Imaging of Patellar Cartilage Degeneration at 0.02 T

MR imaging with a 0.02 T resistive magnet was used to establish the correlation between the histologic grading of patellar cartilage degeneration and fat water separation images or T1- and T2-relaxation times. We examined 23 cadaveric patellae. There was a positive correlation between histologically graded cartilage degeneration and T1-relaxation time. Patellar cartilage was well differentiated from surrounding structures on chemical shift water proton images, and an evaluation of cartilage degeneration was possible. No correlation was found between cartilage damage and T2-relaxation time. Chemical shift imaging at 0.02 T is easy to perform and gives further information of cartilage disorders.

Low-Field Strength Magnetization Transfer Contrast Imaging of the Patellar Cartilage

The time-dependent saturation transfer (TDST) method was applied at 0.1 T in order to evaluate the magnetization transfer contrast (MTC) of the patellar cartilage in vivo. Nine knees were examined. The MTC image of the knee is also demonstrated. The MTC of 63% of the patellar cartilage was attained. Magnetization transfer MR imaging may be of additional help in the evaluation of cartilage disorders at low-field MR imaging.

Synovial cytokine expression in ankle osteoarthritis depends on age and stage

PURPOSE

Aim of the study was the analysis of cytokine expression in ankle osteoarthritis (OA) hypothesizing age-dependent regulation patterns.

METHODS

Forty-nine patients undergoing an arthroscopy of the ankle with different stages of chronic OA were prospectively included in a clinical trial comparing the group <18 years (n = 9, Ø15.1 ± 2.0 years) with the older patients (≥18 years, n = 40, Ø36.5 ± 11.9). Lavage fluids were analysed by ELISA for levels of aggrecan, BMP-2/7, IGF-1/R, bFGF, CD105, MMP-13, and IL-1β. Additionally, clinical parameters and scores (FFI, CFSS, AOFAS) were evaluated and supplemented by radiographic scores [Kellgren-Lawrence Score (KLS) for conventional X-rays, Ankle Osteoarthritis Scoring System (AOSS) for MRI].

RESULTS

In contrast to distribution of gender and BMI (p < 0.005), parameters characterizing the cartilage defect as ICRS grading, size, and duration of symptoms were not dependent on age. The incidence of osteochondritis dissecans (OCD) was higher in the group <18 years (p < 0.006), but the average degree of OCD grading was not different. KLS and AOSS were significantly higher in the group ≥18 years (p < 0.02). Correlating with the higher degree of OA in the elderly, clinical function measured by FFI and AOFAS was statistically significantly worse (p < 0.05). Intra-articular concentrations of aggrecan (3.1-fold), bFGF (8.7-fold), BMP-7 (2.7-fold), and CD105 (1.5-fold) were statistically significantly higher in the group ≥18 years (p < 0.03).

CONCLUSIONS

Confirming the hypothesis, increased synovial levels of aggrecan, bFGF, BMP-7, and CD105 were found in patients over 18 years. This correlated with a higher stage of OA determined by radiographic changes or deteriorated function and may offer starting points for new diagnostics and interventional strategies.

LEVEL OF EVIDENCE

II.

The role of radiology in the evolution of the understanding of articular disease

Both the clinical practice of radiology and the journal Radiology have had an enormous effect on our understanding of articular disease. Early descriptions of osteoarthritis (OA) appeared in Radiology. More recently, advanced physiologic magnetic resonance (MR) techniques have furthered our understanding of the early prestructural changes in patients with OA. Sodium imaging, delayed gadolinium-enhanced MR imaging of cartilage, and spin-lattice relaxation in the rotating frame (or T1ρ) sequences have advanced understanding of the pathophysiology and pathoanatomy of OA. Many pioneering articles on rheumatoid arthritis (RA) also have been published in Radiology. In the intervening decades, our understanding of the natural history of RA has been altered by these articles. Many of the first descriptions of crystalline arthropathies, including gout, calcium pyrophosphate deposition, and hydroxyapatite deposition disease, appeared in Radiology.

Intra-articular injection of mesenchymal stem cells for the treatment of osteoarthritis of the knee: a proof-of-concept clinical trial

Mesenchymal stem cells (MSCs) are known to have a potential for articular cartilage regeneration. However, most studies focused on focal cartilage defect through surgical implantation. For the treatment of generalized cartilage loss in osteoarthritis, an alternative delivery strategy would be more appropriate. The purpose of this study was to assess the safety and efficacy of intra-articular injection of autologous adipose tissue derived MSCs (AD-MSCs) for knee osteoarthritis. We enrolled 18 patients with osteoarthritis of the knee and injected AD MSCs into the knee. The phase I study consists of three dose-escalation cohorts; the low-dose (1.0 × 10(7) cells), mid-dose (5.0 × 10(7)), and high-dose (1.0 × 10(8)) group with three patients each. The phase II included nine patients receiving the high-dose. The primary outcomes were the safety and the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) at 6 months. Secondary outcomes included clinical, radiological, arthroscopic, and histological evaluations. There was no treatment-related adverse event. The WOMAC score improved at 6 months after injection in the high-dose group. The size of cartilage defect decreased while the volume of cartilage increased in the medial femoral and tibial condyles of the high-dose group. Arthroscopy showed that the size of cartilage defect decreased in the medial femoral and medial tibial condyles of the high-dose group. Histology demonstrated thick, hyaline-like cartilage regeneration. These results showed that intra-articular injection of 1.0 × 10(8) AD MSCs into the osteoarthritic knee improved function and pain of the knee joint without causing adverse events, and reduced cartilage defects by regeneration of hyaline-like articular cartilage.

Clinical and radiologic evaluation of arthroscopic medial meniscus root tear refixation: comparison of the modified Mason-Allen stitch and simple stitches

PURPOSE

This study compared the clinical and radiologic outcomes of arthroscopic medial meniscus root refixation using the modified Mason-Allen stitch and simple stitches.

METHODS

The outcomes of 25 patients who underwent arthroscopic meniscus root refixation using the modified Mason-Allen stitch (M group) between June 2010 and January 2012 were compared with those of 25 matched control patients (S group) who underwent meniscus root refixation using simple stitches between March 2004 and August 2007. The Lysholm score, International Knee Documentation Committee Subjective Knee Form score, joint space narrowing, and Kellgren-Lawrence grade were assessed. Medial meniscal extrusion, progression of cartilage degeneration, and healing status of the refixed medial meniscus root were assessed on magnetic resonance images.

RESULTS

No between-group difference was found in age, sex, body mass index, or preoperative patient characteristics. The mean follow-up times for the M and S groups were 24.1 and 25.9 months (P = .248), respectively. The Lysholm, International Knee Documentation Committee Subjective Knee Form, and Tegner activity scores improved significantly in both groups. The repaired root tended to heal better in the M group than in the S group (P = .065). Although the postoperative clinical outcomes did not differ between the groups, postoperative medial meniscal extrusion decreased -0.6 ± 0.9 mm in the M group and increased 1 ± 0.6 mm in the S group on magnetic resonance imaging (P < .001). The M group did not show significant progression in the Kellgren-Lawrence grade and cartilage degeneration (P = .083 and P = .317, respectively), whereas both measures increased significantly in the S group (P = .008 and P < .001, respectively).

CONCLUSIONS

Compared with simple stitches, the modified Mason-Allen stitch improved the degree of meniscal extrusion, although the 2 different suture techniques showed no difference in clinical outcomes at short-term follow-up.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Comparative study on immediate versus delayed meniscus allograft transplantation: 4- to 6-year follow-up

BACKGROUND

Meniscus allograft transplantation (MAT) is generally used for patients who sustain symptoms after meniscectomy, which could be called delayed MAT. Meniscus allograft transplantation for patients immediately after meniscectomy has not been reported.

HYPOTHESIS

Compared with the conventional delayed MAT, immediate MAT might provide better clinical results and reduce joint degeneration.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The study was performed with 18 transplanted menisci (6 medial, 12 lateral) from 16 patients. Eight menisci were transplanted immediately after meniscectomy (IM group); 10 menisci, from patients who complained of knee symptoms at a mean time of 35 months (range, 9-92 months) after total meniscectomy, underwent delayed transplantation (DE group). Fourteen patients undergoing meniscectomy during the same period were included as controls (ME group). Degenerative changes in knee joints were evaluated by plain radiographs and magnetic resonance imaging (MRI). Allograft extrusion and relative percentage of extrusion were measured on MRI. Other outcome assessments included preoperative and postoperative International Knee Documentation Committee (IKDC), Tegner, and Lysholm scores; visual analog scale (VAS) for pain; and range of motion and isokinetic muscle strength evaluation.

RESULTS

The mean length of follow-up was 50.8 months (range, 44-62 months) for the IM group, 72.0 months (range, 44-94 months) for the DE group, and 54.3 months (range, 45-62 months) for the ME group. A statistically significant difference in favor of the IM and ME groups was found on the VAS (0.4 [IM group] vs 1.1 [ME group] vs 2.5 [DE group]) and muscle strength (P < .05). The mean IKDC score in the IM group was significantly higher than that in the DE group (93 [range, 85-99] vs 74 [range, 38-95], respectively; P < .05). The IM group showed significantly less preoperative to postoperative cartilage degeneration changes on radiographs and MRI when compared with the DE and ME groups (Kellgren-Lawrence score changes: 0.25 [IM group] vs 1.0 [DE group] vs 1.7 [ME group]; Yulish score changes: 0.25 [IM group] vs 1.0 [DE group] vs 1.1 [ME group]; P < .05). Extrusion of the allograft was observed in the body of the menisci in all patients. No significant difference was found in terms of the Lysholm score, Tegner score, joint narrowing, or meniscus extrusion (P > .05).

CONCLUSION

Compared with delayed MAT, immediate MAT led to more satisfactory subjective results, less joint degeneration, and less muscle strength deficits. The short-term results of delayed meniscus transplantation were close to those of meniscectomy.

Polyurethane scaffold for the treatment of partial meniscal tears. Clinical results with a minimum two-year follow-up

PURPOSE

to evaluate the safety and effectiveness of the polyurethane meniscal scaffold through clinical examination, MRI and arthroscopic second look, over a minimum two-year follow-up.

METHODS

between 2009 and 2011, 19 patients underwent meniscal scaffold implantation in our department (medial meniscus in 16 cases lateral meniscus in two cases, and bilateral in one case). All the patients were clinically evaluated preoperatively, and at 6, 12, and 24 months after surgery using Lysholm score, Tegner score, and VAS. Ten patients were studied with MRI, and nine patients were evaluated arthroscopically.

RESULTS

no adverse reactions to the implant were observed. The clinical scores showed a significant improvement at 6 months and increased progressively over time. On MRI studies, the implants showed a clear hyperintense signal, sometimes irregular, and the chondral surface was preserved in all cases. At arthroscopic second look in the first months after surgery, the scaffold size was unchanged and the scaffold appeared light yellowish in color and well integrated into the surrounding tissues. At arthroscopic second look at 12 and 24 months the scaffold was found to have an irregular morphology and to be slightly reduced in size.

CONCLUSIONS

polyurethane meniscal scaffold is a good alternative to a collagen scaffold, but a longer follow-up is needed to evaluate the scaffold degradation and chondral coverage.

LEVEL OF EVIDENCE

level IV, therapeutic case series.

Clinical, radiological, and morphological evaluations of posterior horn tears of the lateral meniscus left in situ during anterior cruciate ligament reconstruction

BACKGROUND

Recent studies have shown that lateral menisci have a higher healing potential and that they can be treated successfully without symptoms by being left in situ during anterior cruciate ligament (ACL) reconstruction. However, few studies have reported morphological results.

HYPOTHESIS

Stable posterior horn tears of the lateral meniscus left in situ during ACL reconstruction could be healed spontaneously and would result in not only successful clinical outcomes but also morphological restoration.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Among 367 patients who underwent primary ACL reconstruction between 2008 and 2010, 53 patients who had lateral meniscus tears that were left in situ were analyzed. These patients were evaluated subjectively and radiologically and compared with a matched control group that underwent ACL reconstruction without any other structural disorders. Of the 53 patients with stable posterior horn tears of the lateral meniscus left in situ, 28 patients were assessed by second-look arthroscopic surgery and magnetic resonance imaging (MRI).

RESULTS

The mean follow-up of the study group and the control group was 36.47 and 37.26 months, respectively. There were no statistical differences in postoperative clinical outcomes between the 2 groups. Clinical results of both groups including the Lysholm score, Tegner activity score, and International Knee Documentation Committee (IKDC) score significantly improved. In the subgroup composed of 28 patients, follow-up MRI showed 25 (89%) and 24 (86%) healed menisci in sagittal and coronal views, respectively. Twenty-one (75%) were considered to be completely healed, and 5 (18%) were incompletely healed on second-look arthroscopic surgery.

CONCLUSION

Stable posterior horn tears of the lateral meniscus left in situ at the time of ACL reconstruction revealed successful clinical outcomes compared with isolated ACL injuries and showed considerable healing and functional restoration of tears with repeat MRI and second-look arthroscopic surgery. Therefore, leaving stable posterior horn tears of the lateral meniscus in situ during ACL reconstruction should be considered.

Magnetic resonance imaging is not suitable for interpretation of meniscal status ten years after arthroscopic repair

PURPOSE

The purpose of this study was to assess the MRI features of the all-inside repaired meniscus in the long-term.

METHODS

Among 27 consecutive all-inside arthroscopic meniscal repairs, 23 patients aged 25 ± 5 years at the time of surgery were reviewed at a median follow-up of 10 ± 1 years. Retrospective clinical examinations and imaging assessments using a 1.5-T MRI after all-inside arthroscopic meniscal repair were conducted.

RESULTS

At follow-up, Lysholm and IKDC averaged 89 ± 11 and 95 ± 8, respectively. MRI examinations revealed no meniscal signal alteration in three patients (13%), a vertical signal located in the previously torn area in seven (30%), a horizontal grade 3 in nine (39%), and a complex tear (grade 4) in four (17.5%). There were no differences between medial and lateral menisci (p = 0.15), stable and stabilised knees (p = 0.56).

CONCLUSIONS

Several abnormal vertical and/or horizontal hypersignals are still present on MRI examination ten years after arthroscopic all-inside meniscal repair. The appearance of early signs of osteoarthritis is rare, suggesting a chondroprotective effect of the repaired meniscus.

Arthroscopic collagen meniscus implantation for partial lateral meniscal defects: a 2-year minimum follow-up study

BACKGROUND

Loss of knee meniscal tissue often leads to increased pain and decreased function.

HYPOTHESIS

At a minimum 2-year follow-up, patients receiving a lateral collagen meniscus implant (CMI) would show improved knee function and decreased pain compared with their preoperative status.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twenty-four patients with irreparable lateral meniscal tears (n = 7) or previous partial lateral meniscectomy (n = 17) underwent arthroscopic lateral collagen meniscus implantation. Clinical evaluation was performed preoperatively, at 6 months, and at a minimum 2-year follow-up with Lysholm, visual analog scale (VAS) for pain, Tegner, objective International Knee Documentation Committee (IKDC), and EuroQol 5 dimensions (EQ-5D) scores. A magnetic resonance imaging (MRI) evaluation was performed preoperatively and at final follow-up using the modified Yulish score for cartilage and the Genovese score for implant size and signal intensity.

RESULTS

All clinical scores significantly improved from preoperative evaluation to final follow-up. Average Lysholm scores improved from 64.0 ± 16.2 to 92.7 ± 13.8 (P < .0001), VAS for pain from 55.2 ± 29.4 to 19.5 ± 25.6 (P < .0001), Tegner from 3 (interquartile range, 2-4) to 5 (interquartile range, 4-7) (P = .0062), objective IKDC from 6A, 14B, 4C to 20A, 3B, 1D (P = .0002), and EQ-5D from 0.58 ± 0.28 to 0.89 ± 0.14 (P < .0001). Good to excellent (A + B) objective IKDC scores improved from 83% preoperatively to 96% at 2-year follow-up. The Tegner index (the percentage of the lost activity level that was regained as a result of the treatment intervention) was 47% at 6-month follow-up and 79% at 2-year follow-up: this improvement was statistically significant (P = .0062). The MRI evaluations for tibial and femoral modified Yulish scores for cartilage remained similar over the course of the study; 87.5% of implants were reduced in size, and in 3 cases (12.5%), they were completely resorbed; 50% of the implants had a slightly hyperintense signal (relative to the normal meniscus), and signal intensity changes suggested that full maturation had occurred in 37.5% at final follow-up (based on the Genovese scores).

CONCLUSION

The lateral CMI demonstrated that it was safe in this population study, with decreased pain and improved knee function in 96% of patients with excellent/good Lysholm results in 87% of patients at a minimum 2-year follow-up. The MRI scans demonstrated a decreased implant size relative to a normal meniscus.

Meniscal allograft transplantation without bone plugs: a 3-year minimum follow-up study

BACKGROUND

Meniscal allograft transplantation is a viable option for subtotally meniscectomized and totally meniscectomized symptomatic patients and potentially results in pain relief and increased function.

HYPOTHESIS

The use of a single tibial tunnel arthroscopic technique without bone plugs will reduce symptoms (pain) and improve knee function at a minimum 3-year follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Thirty-two meniscal transplantations (16 medial, 16 lateral; 23 men, 9 women) were prospectively evaluated at a minimum of 36 months (mean, 40.4 ± 6.90 months; range, 36-66 months) after surgery. The average age at the time of surgery was 35.6 ± 10.3 years (range, 15-55 years). The transplantation was performed using an arthroscopic bone plug-free technique with a single tibial tunnel plus "all-inside" meniscal sutures. The anterior meniscal horn was sutured to the capsule. Follow-up included a visual analog scale (VAS) score for knee pain and subjective and objective International Knee Documentation Committee (IKDC), Lysholm, Tegner, and SF-36 scores. All patients underwent radiographic and magnetic resonance imaging (MRI) evaluation of the involved knee before the surgery and at the final follow-up. The MRI outcomes were evaluated with the modified Yulish score.

RESULTS

Regarding clinical evaluation, there was a significant improvement in scores at follow-up compared with preoperatively: the VAS score decreased from 70.6 ± 21.7 to 25.2 ± 22.7 (P < .0001), the SF-36 physical component score increased from 37.31 ± 7.2 to 49.69 ± 8.3 (P < .0001), the SF-36 mental component score increased from 49.69 ± 10.8 to 53.53 ± 7.5 (P = .0032), the Tegner activity score increased from 3 (range, 3-5) to 5 (range, 3-6) (P < .0121), the Lysholm score increased from 59.78 ± 18.25 to 84.84 ± 14.4 (P < .0001), the subjective IKDC score increased from 47.44 ± 20.60 to 77.20 ± 15.57 (P < .0001), and the objective IKDC score changed from 1 A, 21 B, 6 C, and 4 D to 22 A, 9 B, and 1 C (P < .0001). No significant difference was found in this study between patients who received medial allografts and patients who received lateral allografts. There was no significant difference between outcomes of patients with isolated and combined procedures. The MRI findings showed 69% extruded allografts (8 medial and 14 lateral). In detail, we found 50% of the medial allografts and 87% of the lateral allografts extruded. No significant difference in clinical outcomes and modified Yulish score was found between patients with extruded allografts and with in situ allografts. The MRI results also showed a significant decrease of the modified Yulish score from baseline to 3-year minimum follow-up (P < .0001 for femur and P < .0001 for tibia). Only one patient underwent arthroscopic selective meniscectomy because of a medial posterior horn retear of the graft. One patient developed lack of flexion and underwent an arthroscopic arthrolysis. These 2 patients did not draw benefit from allografting and therefore were considered failures. In all remaining cases (94%), meniscal allograft transplantation was able to reduce symptoms (pain measured by VAS) and improve knee function (as measured by IKDC and Lysholm scores).

CONCLUSION

This study found that a single tibial tunnel arthroscopic technique without bone plugs for meniscal allograft transplantation significantly reduced pain and improved knee function in 94% of patients at a minimum 3-year follow-up.

Evaluation of cartilage surface injuries using 3D-double echo steady state (3D-DESS): effect of changing flip angle from 40° to 90°

BACKGROUND

In magnetic resonance imaging (MRI) with 3D-double-echo steady-state (3D-DESS) sequences, the cartilage-synovial fluid contrast is reported to be better with a flip angle of 90° than with the conventional flip angle of 40°, and the detection rate of knee cartilage injury may be improved.

PURPOSE

To compare the diagnostic performance and certainty of diagnosis with 3D-DESS images made using two flip angle settings, 40° and 90°, for knee cartilage surface lesions of Grade 2 or above confirmed by arthroscopy.

MATERIAL AND METHODS

Images were obtained with 3D-DESS flip angles of 40° and 90° at 1.0T in 13 consecutive patients (2 men, 11 women, age range 18-68 years) evaluated for superficial cartilage injury by arthroscopy. Two radiologists classified the presence or absence of cartilage damage of ≥Grade 2 as 'positive (p)' or 'negative (n)', respectively. The rate of agreement with arthroscopic diagnosis was then examined, and the diagnostic performance compared. Diagnostic confidence was assessed scoring the presence or absence of cartilage damage into three categories: 3 = can diagnose with absolute confidence; 2 = can diagnose with a level of certainty as probably present or probably absent; and 1 = cannot make a diagnosis.

RESULTS

In a comparison of the rate of agreement between diagnosis by 3D-DESS images and arthroscopy, the rate of agreement was significantly higher and diagnostic performance was better in 90° images for the medial femoral condyle only. Diagnostic confidence was significantly better with 90° flip angle images than with 40° flip angle images for all six cartilage surfaces.

CONCLUSION

In evaluating knee cartilage surface lesions with 3D-DESS sequences, a flip angle setting of 90° is more effective than the conventional setting of 40°.

Arthroscopic lateral collagen meniscus implant in a professional soccer player

A case of an arthroscopically implanted lateral Collagen Meniscus Implant in a 24-year-old professional soccer player is reported. This meniscal scaffold was able to improve knee function and reduce pain in this symptomatic meniscectomized young athlete at 36-month follow-up. This is the first case of an arthroscopic lateral collagen meniscal scaffold implanted in a high-level soccer player described in literature.

Prospective long-term outcomes of the medial collagen meniscus implant versus partial medial meniscectomy: a minimum 10-year follow-up study

BACKGROUND

Loss of meniscal tissue can be responsible for increased pain and decreased function.

HYPOTHESIS

At a minimum 10-year follow-up, patients receiving a medial collagen meniscus implant (MCMI) would show better clinical, radiological, and magnetic resonance imaging (MRI) outcomes than patients treated with partial medial meniscectomy (PMM).

STUDY DESIGN

Cohort study; Level of evidence 2.

METHODS

Thirty-three nonconsecutive patients (men; mean age, 40 years) with meniscal injuries were enrolled in the study to receive MCMI or to serve as a control patient treated with PMM. The choice of treatment was decided by the patient. All patients were clinically evaluated at time 0 and at 5 years and a minimum of 10 years after surgery (mean follow-up, 133 months) by Lysholm, visual analog scale (VAS) for pain, objective International Knee Documentation Committee (IKDC) knee form, and Tegner activity level scores. The SF-36 score was performed preoperatively and at final follow-up. Bilateral weightbearing radiographs were completed before the index surgery and at final follow-up. Minimum 10-year follow-up MRI images were compared with preoperative MRI images by means of the Yulish score. The Genovese score was also used to evalute MCMI MRI survivorship.

RESULTS

The MCMI group, compared with the PMM one, showed significantly lower VAS for pain (1.2 ± 0.9 vs 3.3 ± 1.8; P = .004) and higher objective IKDC (7A and 10B for MCMI, 4B and 12C for PMM; P = .0001), Teger index (75 ± 27.5 vs 50 ± 11.67; P = .026), and SF-36 (53.9 ± 4.0 vs 44.1 ± 9.2; P = .026 for Physical Health Index; 54.7 ± 3.8 vs 43.8 ± 6.5; P = .004 for Mental Health Index) scores. Radiographic evaluation showed significantly less medial joint space narrowing in the MCMI group than in the PMM group (0.48 ± 0.63 mm vs 2.13 ± 0.79 mm; P = .0003). No significant differences between groups were reported regarding Lysholm (P = .062) and Yulish (P = .122) scores. Genovese score remained constant between 5 and 10 years after surgery (P = .5). The MRI evaluation of the MCMI patients revealed 11 cases of myxoid degeneration signal: 4 had a normal signal with reduced size, and 2 had no recognizable implant.

CONCLUSION

Pain, activity level, and radiological outcomes are significantly improved with use of the MCMI at a minimum 10-year follow-up compared with PMM alone. Randomized controlled trials on a larger population are necessary to confirm MCMI benefits at long term.

Follow-up of collagen meniscus implant patients: clinical, radiological, and magnetic resonance imaging results at 5 years

This study investigated at medium term follow-up the clinical outcomes and any progression of knee osteoarthritis in a population of patients that underwent arthroscopic placement of a collagen meniscus implant. Thirty-four patients underwent arthroscopic placement of a collagen meniscus implant for a symptomatic deficiency of medial meniscal tissue. Follow-up evaluation included Lysholm II score and Tegner activity scores and MR arthrography of the knee at 2 and 5 years after surgery. Plain radiographs were also obtained at 5 years. Six patients were excluded. In eight cases arthroscopic second look evaluation was performed. Lysholm and Tegner activity scores at 2 and 5 years after surgery improved significantly compared to the preoperative score. These patients showed good to excellent clinical results after 5 years from a CMI placement. The chondral surfaces of the medial compartment had not degenerated further since placement of the CMI. MR signal had continued to mature between 2 and 5 years after implant, progressively decreasing signal intensity but in any case comparable to the low signal of a normal meniscus. In most of cases the CMI-new tissue complex had a slight reduction in size, compared to a normal medial meniscus, but the new tissue had no apparent negative effects.

Bone marrow oedema of the knee

Magnetic resonance (MR) imaging is a frequently performed investigation for disease of the knee. Bone marrow oedema (BME) is a common MR finding with a number of causes including trauma, tumour, infection, inflammatory arthropathies and BME syndromes. This article illustrates the range of MR appearances of BME around the knee and describes secondary signs that allow the reader to determine the cause of disease and to distinguish BME from normal marrow signal changes.

Risk factors for articular cartilage lesions in symptomatic discoid lateral meniscus

PURPOSE

To investigate risk factors related to articular cartilage lesions in discoid lateral meniscus (DLM) and to analyze the possible mechanisms associated with articular cartilage lesions.

METHODS

From October 2004 to April 2008, 103 knees in 97 patients with DLM confirmed by arthroscopy were operated on at our clinical center. Among them, 16 knees were accompanied by articular cartilage injury. Data on risk factors, including patient age, traumatic history, DLM type, presence or absence of tear, symptomatic duration, and meniscal shape, were analyzed to investigate the relation with articular cartilage lesion by logistic regression analysis.

RESULTS

Only symptomatic duration and meniscal shape had a significant relation with articular cartilage lesion. Symptomatic duration and meniscal shape can be regarded as risk factors, and their odds ratios were 4.983 (P < .01) and 5.356 (P < .05), respectively.

CONCLUSIONS

Long symptomatic duration (>6 months) and asymmetrical shape of DLM were more frequently related to articular cartilage lesions than other factors.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Magnetic resonance imaging of the femoral trochlea: evaluation of anatomical landmarks and grading articular cartilage in cadaveric knees

PURPOSE

The purpose of the study was to define magnetic resonance imaging (MRI) findings before and after contrast medium opacification of the knee joint in cadaveric specimens to demonstrate anatomical landmarks of the trochlear surface in relation to the neighboring structures, and to evaluate different MRI sequences in the detection of cartilage defects of the trochlear and patellar surface of the knee.

MATERIALS AND METHODS

The morphology and relationship of the proximal trochlear surface to the prefemoral fat of the distal femur were investigated by use of different MR sequences before and after intra-articular gadolinium administration into the knee joint in ten cadaveric knees. Anatomic sections were subsequently obtained. In addition, evaluation of the articular surface of the trochlea was performed by two independent observers. The cartilage surfaces were graded using a 2-point system, and results were compared with macroscopic findings.

RESULTS

Of 40 cartilage surfaces evaluated, histopathologic findings showed 9 normal surfaces, 20 containing partial-thickness defects, and 11 containing full-thickness defects. Compared with macroscopic data, sensitivity of MR sequences for the two reviewers was between 17 and 90%; specificity, 75 and 100%; positive predictive value, 75 and 100%; negative predictive value, 20 and 100%, depending on patellar or trochlea lesions. Interobserver variability for the presence of disease, which was measured using the kappa statistic, was dependent on the MR sequence used between 0.243 and 0.851.

CONCLUSION

Magnetic resonance imaging sequences can be used to evaluate the cartilage of the trochlear surface with less accuracy when compared with the results of grading the articular cartilage of the patella.

Magnetic resonance imaging for diagnosis and assessment of cartilage defect repairs

Clinical magnetic resonance imaging (MRI) is the method of choice for the non-invasive evaluation of articular cartilage defects and the follow-up of cartilage repair procedures. The use of cartilage-sensitive sequences and a high spatial-resolution technique enables the evaluation of cartilage morphology even in the early stages of disease, as well as assessment of cartilage repair. Sequences that offer high contrast between articular cartilage and adjacent structures, such as the fat-suppressed, 3-dimensional, spoiled gradient-echo sequence and the fast spin-echo sequence, are accurate and reliable for evaluating intrachondral lesions and surface defects of articular cartilage. These sequences can also be performed together in reasonable examination times. In addition to morphology, new MRI techniques provide insight into the biochemical composition of articular cartilage and cartilage repair tissue. These techniques enable the diagnosis of early cartilage degeneration and help to monitor the effect and outcome of various surgical and non-surgical cartilage repair therapies.

Do MRI features at baseline predict radiographic joint space narrowing in the medial compartment of the osteoarthritic knee 2 years later?

PURPOSE

The purpose of the study was to relate magnetic resonance imaging (MRI) features at baseline with radiographically determined joint space narrowing (JSN) in the medial compartment of the knee after 2 years in a group of patients with symptomatic osteoarthritis at multiple joint sites.

MATERIALS AND METHODS

MRI of the knee and standardized radiographs were obtained at baseline and after 2 years in 186 patients (81% female; aged 43-76 years; mean 60 years). MRI was analyzed for bone marrow lesions, cysts, osteophytes, hyaline cartilage defects, joint effusion, and meniscal pathology in the medial compartment. Radiographs were scored semiquantitatively for JSN in the medial tibiofemoral joint using the Osteoarthritis Research Society International (OARSI) atlas. Radiological progression was defined as > or =1 grade increase. Associations between baseline magnetic resonance (MR) parameters and subsequent radiographic JSN changes were assessed using logistic regression. Relative risk (RR) was then calculated.

RESULTS

Radiographic progression of JSN was observed in 17 (9.1%) of 186 patients. Eleven patients had a Kellgren and Lawrence (KL) score of > or =2. A significant association was observed between all patients and meniscal tears (RR 3.57; confidence interval (CI) 1.08-10.0) and meniscal subluxation (RR 2.73; CI 1.20-5.41), between KL < 2 and meniscal subluxation (RR 11.3; CI 2.49-29.49) and KL > or = 2 and meniscus tears (RR 8.91; CI 1.13-22.84) and radiographic JSN 2 years later. Follow-up MR in 15 of 17 patients with progressive JSN showed only new meniscal abnormalities and no progression of cartilage loss.

CONCLUSION

Meniscal pathology (tears and/or meniscal subluxation) was the only MRI parameter to be associated with subsequent radiographic progression of JSN in the medial tibiofemoral compartment on a radiograph 2 years later, as assessed by the OARSI score.

Accuracy of MRI diagnosis of internal derangement of the knee in a non-specialized tertiary level referral teaching hospital

This study was designed to assess the accuracy of knee MRI examinations carried out in a general tertiary referral hospital without a musculoskeletal fellowship trained radiologist. The study included all patients who had undergone a knee arthroscopy carried out within a 2-year period and who had had a prior MRI knee examination, where both were carried out at this institution. The accuracy of the MRI knee examination was determined by correlation to the arthroscopy report. The accuracy for diagnosis of meniscal and cartilage injuries, in this setting, was found to be similar to a published meta-analysis of previous studies correlating knee MRI and arthroscopy. The overall accuracy of this study was better than the previous similar study. However, the accuracy for diagnosing ACL injuries was lower than in the meta-analysis. The potential reasons for this and other sources of error are discussed.

Arthroscopic estimation of the extent of chondropathy

INTRODUCTION

Arthroscopy has been used to evaluate articular cartilage (AC) pathology in osteoarthritis (OA) for outcome measurement and validation of non-invasive imaging. However, many fundamental aspects of arthroscopic assessment remain un-validated.

OBJECTIVES

This study evaluated arthroscopic estimates of extent of chondropathy.

METHODS

Serial arthroscopic assessments were performed in a group of 15 sheep before and after bilateral stifle medial meniscectomy (MMx). Post-mortem assessments were performed in un-MMx sheep and 4 and 16 weeks post-MMx. Arthroscopic assessments of the extent of each grade of chondropathy were compared with a non-arthroscopic hybrid assessment that incorporated biomechanical, thickness and macroscopic assessments.

RESULTS

Arthroscopy evaluated only 36% of AC and missed significant pathological changes, softening and chondro-osteophyte, occurring in peripheral regions. The patterns of change in arthroscopic assessments were similar to those of the non-arthroscopic assessment but there was a very strong tendency to over-estimate the extent of softened AC after MMx. In spite of these limitations arthroscopic assessments were responsive to change. Estimates of the extent of normal and softened AC were most responsive to change over time followed by estimates of superficial and deep fibrillation. Arthroscopy was as an excellent discriminator between normal and OA. Assessments of chondro-osteophyte and exposed bone were not responsive to change.

CONCLUSIONS

Arthroscopic estimates of extent of chondropathy are prone to substantial error. While experience and training may reduce these errors other approaches may more effectively improve performance.

Diagnosis of articular cartilage abnormalities of the knee: prospective clinical evaluation of a 3D water-excitation true FISP sequence

PURPOSE

To prospectively evaluate the accuracy of three-dimensional (3D) water-excitation true fast imaging with steady-state precession (FISP) in the assessment of cartilage abnormalities of the knee, by using surgery as the reference standard.

MATERIALS AND METHODS

The study was approved by the hospital institutional review board. Written informed consent was obtained from all patients. Twenty-nine patients (30 knees) with a mean age of 56 years (range, 18-86 years) were prospectively evaluated with a sagittal 3D true FISP magnetic resonance (MR) sequence. The mean interval between MR imaging and surgery was 1 day (range, 0-9 days). During surgery, the articular surfaces of the knee were evaluated by using a modified Noyes score. The MR images were evaluated by two blinded readers on two separate occasions. Diagnostic performance was evaluated by setting the cutoff for abnormality between grade 1 (intact cartilage surface) and grade 2 (cartilage defects). Statistical methods used included calculation of sensitivity, specificity, and accuracy, with 95% confidence intervals (Wilson score method) and calculation of kappa values with standard errors.

RESULTS

Overall sensitivity, specificity, and accuracy for the two readers and the two evaluations ranged from 56% to 66%, 78% to 93%, and 71% to 75%, respectively. Interobserver agreement was substantial for both the first (kappa = 0.73) and the second (kappa = 0.65) evaluation. Intraobserver agreement was almost perfect (kappa = 0.84) for reader 1 and moderate (kappa = 0.60) for reader 2.

CONCLUSION

The 3D water-excitation true FISP MR sequence allows assessment of the articular cartilage of the knee with moderate-to-high specificity and low-to-moderate sensitivity.

Is cartilage thickness different in young subjects with and without patellofemoral pain?

OBJECTIVE

To determine the differences in load-bearing patellofemoral joint cartilage thickness between genders. To determine the differences in load-bearing cartilage thickness between pain-free controls and individuals with patellofemoral pain.

METHODS

The articular cartilage thickness of the patella and anterior femur was estimated from magnetic resonance images in 16 young, pain-free control subjects (eight males, eight females) and 34 young individuals with patellofemoral pain (12 males, 22 females). The average age of all subjects was 28+/-4 years. The cartilage surfaces were divided into regions approximating the location of patellofemoral joint contact during knee flexion. The mean and peak cartilage thicknesses of each region were computed and compared using a repeated-measures Analysis of Variance.

RESULTS

On average, males had 22% and 23% thicker cartilage than females in the patella (P < 0.01) and femur (P < 0.05), respectively. Male control subjects had 18% greater peak patellar cartilage thickness than males with patellofemoral pain (P < 0.05); however, we did not detect differences in patellar cartilage thickness between female control subjects and females with patellofemoral pain (P = 0.45). We detected no significant differences in femoral cartilage thickness between the control and pain groups.

CONCLUSIONS

Thin cartilage at the patella may be one mechanism of patellofemoral pain in male subjects, but is unlikely to be a dominant factor in the development of pain in the female population.

Meniscal allograft transplantation: long-term clinical results with radiological and magnetic resonance imaging correlations

Long-term data on the clinical outcome and the fate of the meniscus allograft after transplantation are scarce. In this study we present the clinical, radiological and MRI outcome of the meniscus graft and the articular cartilage after 42 meniscus allograft transplantations in 41 patients with a minimum follow-up of 10 years. A total of 27 medial and 15 lateral meniscal allografts were transplanted. Eleven of the medial allograft procedures were associated with a high tibial osteotomy. The patients were evaluated clinically at the time of transplantation and at the final follow-up using the modified HSS scoring system. The knee injury and osteoarthritis outcome score (KOOS) was used as an evaluation tool for patient-related outcome at the final follow-up. Joint space width narrowing and Fairbank changes were radiological outcome parameters, which were available for 32 patients. Femoral and tibial cartilage degeneration, graft extrusion and signal intensity were scored on MRI scans obtained in 17 patients approximately 1 year after transplantation and at the final follow-up (>10 years). For statistical analysis the patients were divided into three groups: lateral meniscal allograft (LMT), medial meniscal allograft transplantation with a high tibial osteotomy (MMT+HTO) and without (MMT). The modified HSS score revealed a significant improvement in pain and function at the final follow-up for all groups. Further analysis also revealed that an MMT+HTO procedure resulted in a greater improvement at the final follow-up when compared to MMT. Nonetheless, the KOOS scores obtained at the final follow-up revealed the presence of substantial disability and symptoms, in addition to a reduced quality of life. Radiographical analysis revealed no further joint space narrowing in 13/32 knees (41%). Fairbank changes remained stable in 9/32 knees (28%). MRI analysis showed no progression of cartilage degeneration in 6/17 knees (35%). An increased signal intensity of the allograft was present, as was partial graft extrusion in the majority of patients at the final follow-up. Seven cases had to be converted to a total knee arthroplasty during the follow-up; the overall failure rate was 18%. Long-term results after viable meniscus allograft transplantation are encouraging in terms of pain relief and improvement of function. Despite this significant improvement, substantial disability and symptoms were present in all investigated subgroups. Progression of further cartilage degeneration or joint space narrowing was absent in a considerable number of cases, indicating a potential chondroprotective effect. Level of evidence is therapeutic study, Level IV and retrospective analysis of prospectively collected data.

Osteoarthritis of the knee: association between clinical features and MR imaging findings

PURPOSE

To prospectively evaluate the association between clinical features and structural abnormalities found at magnetic resonance (MR) imaging in patients with osteoarthritis (OA) of the knee.

MATERIALS AND METHODS

The study was approved by the institutional medical ethics review board. Written informed consent was obtained from each patient. MR images of the knee were obtained from 205 (42 [20%] men, 163 [80%] women; median age, 60 years; range, 43-77 years) patients in whom symptomatic OA at multiple joint sites was diagnosed. MR images were analyzed for various abnormalities of OA. All patients were interviewed concerning pain and stiffness in the knee that was imaged. Odds ratios (ORs) with 99% confidence intervals (CIs) were used to determine the association between the imaging findings and clinical features of OA.

RESULTS

A large joint effusion was associated with pain (OR, 9.99; 99% CI: 1.28, 149) and stiffness (OR, 4.67; 99% CI: 1.26, 26.1). The presence of an osteophyte in the patellofemoral compartment (OR, 2.25; 99% CI: 1.06, 4.77) was associated with pain. All other imaging findings, including focal or diffuse cartilaginous abnormalities, subchondral cysts, bone marrow edema, subluxation of the meniscus, meniscal tears, or Baker cysts, were not associated with symptoms.

CONCLUSION

Findings of this study indicate that only two associations exist between clinical symptoms and structural findings found on MR images in patients with OA of the knee.