Long-term outcome of meniscectomy: symptoms, function, and performance tests in patients with or without radiographic osteoarthritis compared to matched controls

Determination of the safe penetration depth during all-inside meniscal repair of the posterior part of the lateral meniscus using the FasT-Fix suture repair system

PURPOSE

The objective of this study was to determine the safe penetration depth of the FasT-Fix meniscal suture repair system during all-inside repair of the posterior part of the lateral meniscus.

METHODS

Thirty-one knees from 17 embalmed and formalin-fixed cadavers (11 women, 6 men) were used. In each case, the circumference of the cadaver knee was measured before dissection. After dissection, 41 Fast-Fix meniscal repair devices were used in different predetermined penetration depths ranging from 8 to 16 mm. In this study, non-involvement of the popliteal neurovascular bundle, common peroneal nerve or the inferior lateral genicular vessels by either needle penetration or affixment by the suture bar anchors was considered to be a safe trial.

RESULTS

Out of the 41 FasT-Fix devices used in this study, only one device bent during introduction and was excluded from the study. For the remaining 40 trials, 27 of them were considered safe, while 13 trials were considered unsafe. The ratio of the average penetration depth to the average circumference of the cadaver knee was found to be >0.05 for the unsafe penetrations, and this was statistically significant P < 0.05. Additionally, for the first point, which is more central, there was a trend for the straight needles through the direct lateral approach to be less safe, and this was found to be statistically significant P < 0.05.

CONCLUSIONS

Correlating the needle-penetration depth to the measured circumference of the cadaver knee may be an important clinical predictor of safety whereby a ratio of less than 0.05 might be useful as a guide to determine the safe penetration depth of the FasT-Fix suture repair needle during repair of the posterior horn lateral meniscus. Also, it is better to avoid using straight needles through the direct lateral approach during repair of the more central portion of the posterior horn lateral meniscus.

Landing adaptations following isolated lateral meniscectomy in athletes

PURPOSE

Objective functional outcomes following isolated radial lateral meniscus tears in the athlete between the ages of 14-25 are not clearly defined. The objective of this study was to determine whether patients following lateral meniscectomy demonstrate lower extremity asymmetries relative to control athletes 3 months after surgery. We hypothesized that following lateral meniscectomy, athletes aged 14-25 years old would demonstrate altered landing biomechanics compared to sex, age, height, weight, and sport-matched controls.

METHODS

A total of 18 subjects were included in this study. Nine patients (7 men and 2 women, 20.1 ± 2.8 years) who had undergone first-time isolated radial lateral meniscus tears were tested 3 months following partial lateral meniscectomies and compared to nine sex, age, height, weight, and sport-matched controls (7 men and 2 women, 19.7 ± 3.1 years). A ten-camera motion analysis system and two force platforms were used to collect three trials of bilateral drop landings. A 2X2 ANOVA was used to test the interaction between side (involved vs. uninvolved) and group (patient vs. control).

RESULTS

The patient group landed with a decreased internal knee extensor moment compared to the uninvolved side and controls (interaction P < 0.05). The involved limb quadriceps isokinetic torque was not decreased compared to the contralateral or control (n.s.). Decreased knee extensor moments were significantly associated with reduced measures of function (IKDC scores: r = 0.69; P < 0.05).

CONCLUSIONS

Athletes who return to sport at approximately 3 months following a partial lateral meniscectomy may employ compensation strategies during landing as evidenced by reduced quadriceps recruitment and functional outcome scores. Clinicians should focus on improving quadriceps function during landing on the involved leg in an attempt to decrease residual limb asymmetries.

LEVEL OF EVIDENCE

Case-control study, Level III.

The knee meniscus: structure-function, pathophysiology, current repair techniques, and prospects for regeneration

Extensive scientific investigations in recent decades have established the anatomical, biomechanical, and functional importance that the meniscus holds within the knee joint. As a vital part of the joint, it acts to prevent the deterioration and degeneration of articular cartilage, and the onset and development of osteoarthritis. For this reason, research into meniscus repair has been the recipient of particular interest from the orthopedic and bioengineering communities. Current repair techniques are only effective in treating lesions located in the peripheral vascularized region of the meniscus. Healing lesions found in the inner avascular region, which functions under a highly demanding mechanical environment, is considered to be a significant challenge. An adequate treatment approach has yet to be established, though many attempts have been undertaken. The current primary method for treatment is partial meniscectomy, which commonly results in the progressive development of osteoarthritis. This drawback has shifted research interest toward the fields of biomaterials and bioengineering, where it is hoped that meniscal deterioration can be tackled with the help of tissue engineering. So far, different approaches and strategies have contributed to the in vitro generation of meniscus constructs, which are capable of restoring meniscal lesions to some extent, both functionally as well as anatomically. The selection of the appropriate cell source (autologous, allogeneic, or xenogeneic cells, or stem cells) is undoubtedly regarded as key to successful meniscal tissue engineering. Furthermore, a large variation of scaffolds for tissue engineering have been proposed and produced in experimental and clinical studies, although a few problems with these (e.g., byproducts of degradation, stress shielding) have shifted research interest toward new strategies (e.g., scaffoldless approaches, self-assembly). A large number of different chemical (e.g., TGF-β1, C-ABC) and mechanical stimuli (e.g., direct compression, hydrostatic pressure) have also been investigated, both in terms of encouraging functional tissue formation, as well as in differentiating stem cells. Even though the problems accompanying meniscus tissue engineering research are considerable, we are undoubtedly in the dawn of a new era, whereby recent advances in biology, engineering, and medicine are leading to the successful treatment of meniscal lesions.

Greater than 10-year results of red-white longitudinal meniscal repairs in patients 20 years of age or younger

BACKGROUND

A prospective longitudinal investigation was conducted to determine the long-term outcome of single longitudinal meniscal repairs extending into the central avascular region in patients aged 20 years or younger.

PURPOSE

To determine the long-term success rate and reoperation rate of meniscal repairs extending into the avascular zone.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Thirty-three meniscal repairs were performed using an inside-out multiple vertical divergent suture technique. A concomitant anterior cruciate ligament reconstruction was done in 18 patients. The mean follow-up was 16.8 years (range, 10.1-21.9 years). The long-term success rate was determined in 29 repairs (88%) by the presence of normal or nearly normal parameters from 2 validated knee rating systems, assessment of magnetic resonance imaging and weightbearing posteroanterior radiographs by independent physicians, and follow-up arthroscopy when required. A 3 Tesla magnetic resonance imaging scanner with cartilage-sensitive pulse sequences was used, and T2 mapping was performed. A comparison was made between the short-term (mean, 4 years) and long-term outcomes.

RESULTS

Eighteen (62%) of the meniscal repairs had normal or nearly normal characteristics in all of the parameters assessed. Six repairs (21%) required partial arthroscopic resection, 2 had loss of joint space on radiographs, and 3 that were asymptomatic failed according to magnetic resonance imaging criteria, for a total of 11 documented failures (38%). There was no significant difference in the mean articular cartilage T2 scores in the healed menisci between the involved and contralateral tibiofemoral compartments in the same knee. There were no significant differences between short- and long-term evaluations for pain, swelling, jumping, patient knee condition rating, or the overall Cincinnati rating score.

CONCLUSIONS

A chondroprotective joint effect was demonstrated in the healed menisci repairs, which warrants the procedure in select patients. The long-term evaluation of the anterior cruciate ligament-reconstructed knees with concurrent successful meniscal repairs demonstrated a low rate of radiographic arthritis.

Guidelines for the Design and Conduct of Clinical Studies in Knee Articular Cartilage Repair: International Cartilage Repair Society Recommendations Based on Current Scientific Evidence and Standards of Clinical Care

OBJECTIVE

To summarize current clinical research practice and develop methodological standards for objective scientific evaluation of knee cartilage repair procedures and products.

DESIGN

A comprehensive literature review was performed of high-level original studies providing information relevant for the design of clinical studies on articular cartilage repair in the knee. Analysis of cartilage repair publications and synopses of ongoing trials were used to identify important criteria for the design, reporting, and interpretation of studies in this field.

RESULTS

Current literature reflects the methodological limitations of the scientific evidence available for articular cartilage repair. However, clinical trial databases of ongoing trials document a trend suggesting improved study designs and clinical evaluation methodology. Based on the current scientific information and standards of clinical care, detailed methodological recommendations were developed for the statistical study design, patient recruitment, control group considerations, study endpoint definition, documentation of results, use of validated patient-reported outcome instruments, and inclusion and exclusion criteria for the design and conduct of scientifically sound cartilage repair study protocols. A consensus statement among the International Cartilage Repair Society (ICRS) and contributing authors experienced in clinical trial design and implementation was achieved.

CONCLUSIONS

High-quality clinical research methodology is critical for the optimal evaluation of current and new cartilage repair technologies. In addition to generally applicable principles for orthopedic study design, specific criteria and considerations apply to cartilage repair studies. Systematic application of these criteria and considerations can facilitate study designs that are scientifically rigorous, ethical, practical, and appropriate for the question(s) being addressed in any given cartilage repair research project.

Does arthroscopic partial meniscectomy result in knee osteoarthritis? A systematic review with a minimum of 8 years' follow-up

PURPOSE

Our purpose is to test the hypothesis that arthroscopic partial meniscectomy results in knee osteoarthritis at long-term follow-up.

METHODS

We systematically reviewed PubMed search terms "meniscus AND arthritis AND knee" and "meniscectomy AND arthritis AND knee" and included English-language, Levels I to IV evidence studies reporting either radiographic or clinical osteoarthritis outcome measures with a minimum of 8 years' follow-up after partial arthroscopic meniscectomy.

RESULTS

Five studies met the inclusion criteria. All reported both radiographic and clinical measures. All studies compared the normal, contralateral knee as a radiographic control, but none included a clinical control group. Follow-up ranged from 8 to 16 years. In all studies operative knees showed a statistically significant incidence of radiographic signs of osteoarthritis compared with control knees. However, clinical symptoms of osteoarthritis were not observed. Furthermore, clinical outcomes did not correlate with radiographic findings.

DISCUSSION

Our results show that radiographic signs of osteoarthritis are significant at 8 to 16 years' follow-up after knee arthroscopic partial meniscectomy, but clinical symptoms of knee arthritis were not observed. Limitations include absence of clinical control groups and heterogeneity of reported outcome measures. Future research of higher levels of evidence and with longer-term follow-up is required to determine whether the radiographic signs ultimately foreshadow clinical symptoms in patients after arthroscopic partial meniscectomy.

CONCLUSIONS

Radiographic signs of osteoarthritis are significant at 8 to 16 years' follow-up after knee arthroscopic partial meniscectomy, but clinical symptoms of knee arthritis are not significant.

LEVEL OF EVIDENCE

Systematic review of Level IV clinical evidence and Levels II and III radiographic evidence.

Meniscectomy as a risk factor for knee osteoarthritis: a systematic review

INTRODUCTION

This review defines the recognized risk factors responsible for the development of knee osteoarthritis after surgical management of meniscal tears.

SOURCES OF DATA

We performed a literature search using Medline, Ovid, Cochrane and Google Scholar using the keywords: 'Meniscal tears', 'meniscectomy', 'osteoarthritis', 'complications' and 'risk factors'. Thirty-two published studies were identified.

AREAS OF AGREEMENT

In the long term, osteoarthritis develops in the knee of patients undergoing surgery for meniscal tears. The Coleman methodology score showed great heterogeneity in terms of patient characteristics and outcome assessment. Amount of meniscus removed, duration of pre-operative symptoms and lateral meniscectomy show strong statistical association to onset of knee osteoarthritis.

AREAS OF CONTROVERSY

We did not find univocal findings defining the risk factors responsible for the development of post-operative knee osteoarthritis.

GROWING POINTS

There is a need for standardized clinical and imaging validated scale to improve definition of post-operative knee osteoarthritis to allow easier and more reliable comparison of outcomes in different studies.

AREAS TIMELY FOR DEVELOPING RESEARCH

Appropriately powered randomized controlled trials reporting clinical and imaging-related outcomes in patients undergoing arthroscopic minimally invasive procedures and meniscal suturing should be performed. Comparing imaging findings of patients undergoing arthroscopic partial and open meniscectomy, a lower incidence of knee osteoarthritic evolution was detected after arthroscopy. The amount of removed meniscus is the most important predictor factor for the development of osteoarthritis. Minimally invasive procedures seem to reduce the incidence of long-term osteoarthritic changes of the knee compared with more invasive open and or arthroscopic procedures.

Which preoperative factors, including bone bruise, are associated with knee pain/symptoms at index anterior cruciate ligament reconstruction (ACLR)? A Multicenter Orthopaedic Outcomes Network (MOON) ACLR Cohort Study

BACKGROUND

Increased knee pain at the time of anterior cruciate ligament reconstruction may potentially predict more difficult rehabilitation, prolonged recovery, and/or be predictive of increased knee pain at 2 years.

HYPOTHESIS

A bone bruise and/or other preoperative factors are associated with more knee pain/symptoms at the time of index anterior cruciate ligament reconstruction, and the presence of a bone bruise would be associated with specific demographic and injury-related factors.

STUDY DESIGN

Cohort study (prevalence); Level of evidence, 2.

METHODS

In 2007, the Multicenter Orthopaedic Outcomes Network (MOON) database began to prospectively collect surgeon-reported magnetic resonance imaging bone bruise status. A multivariable analysis was performed to (1) determine if a bone bruise, among other preoperative factors, is associated with more knee symptoms/pain and (2) examine the association of factors related to bone bruise. To evaluate the association of a bone bruise with knee pain/symptoms, linear multiple regression models were fit using the continuous scores of the Knee injury and Osteoarthritis Outcome Score (KOOS) symptoms and pain subscales and the Short Form 36 (SF-36) bodily pain subscale as dependent variables. To examine the association between a bone bruise and risk factors, a logistic regression model was used, in which the dependent variable was the presence or absence of a bone bruise.

RESULTS

Baseline data for 525 patients were used for analysis, and a bone bruise was present in 419 (80%). The cohort comprises 58% male patients, with a median age of 23 years. The median Marx activity level was 13. Factors associated with more pain were higher body mass index (P < .0001), female sex (P = .001), lateral collateral ligament injury (P = .012), and older age (P = .038). Factors associated with more symptoms were a concomitant lateral collateral ligament injury (P = .014), higher body mass index (P < .0001), and female sex (P < .0001). Bone bruise is not associated with symptoms/pain at the time of index anterior cruciate ligament reconstruction. None of the factors included in the SF-36 bodily pain model were found to be significant. After controlling for other baseline factors, the following factors were associated with a bone bruise: younger age (P = .034) and not jumping at the time of injury (P = .006).

CONCLUSION

After anterior cruciate ligament injury, risk factors associated with a bone bruise are younger age and not jumping at the time of injury. Bone bruise is not associated with symptoms/pain at the time of index anterior cruciate ligament reconstruction.

A systematic review of clinical outcomes in patients undergoing meniscectomy

Knee meniscectomy is the most common procedure performed by orthopaedic surgeons. While it is generally believed that loss of meniscal tissue leads to osteoarthritis and poor knee function, many variables may significantly influence this outcome. Through literature search engines including PubMed and Ovid, 4 randomized controlled trials, 2 prospective cohorts, and 23 retrospective cohorts that fit the criteria for level I, II, and III level of evidence were included in this systematic review. For the level III evidence studies, follow-up of 5 years or more was required. Preoperative and intraoperative predictors of poor clinical or radiographic outcomes included total meniscectomy or removal of the peripheral meniscal rim, lateral meniscectomy, degenerative meniscal tears, presence of chondral damage, presence of hand osteoarthritis suggestive of genetic predisposition, and increased body mass index. Variables that were not predictive of outcome or were inconclusive or had mixed results included meniscal tear pattern, age, mechanical alignment, sex of patient, activity level, and meniscal tears associated with anterior cruciate ligament (ACL) reconstruction. While an intact meniscus or meniscal repair was generally favorable in the ACL-reconstructed knees, meniscal repair of degenerative meniscal tissue was not favorable. There is a lack of uniformity in the literature on this subject with a preponderance of lower level evidence. Although randomized controlled trials are considered to be the gold standard in medical research, a multicenter prospective cohort design may be more appropriate in assessing the long-term outcome of meniscal surgery and the role that multiple preoperative and intraoperative variables may play in clinical outcomes. In addition, future studies should include factors not assessed or adequately evaluated by several of the included studies, such as meniscal tear pattern, age, mechanical alignment, sex of the patient, activity level, meniscal tears associated with other injuries such as the ACL, smoking, and the effect of previous surgery.

Epidemiology of osteoarthritis

Osteoarthritis (OA) is the most common joint disorder in the United States. Symptomatic knee OA occurs in 10% men and 13% in women aged 60 years or older. The number of people affected with symptomatic OA is likely to increase due to the aging of the population and the obesity epidemic. OA has a multifactorial etiology, and can be considered the product of an interplay between systemic and local factors. Old age, female gender, overweight and obesity, knee injury, repetitive use of joints, bone density, muscle weakness, and joint laxity all play roles in the development of joint OA, particularly in the weight-bearing joints. Modifying these factors may reduce the risk of OA and prevent subsequent pain and disability.

Quantitative magnetic resonance imaging detects changes in meniscal volume in vivo after partial meniscectomy

BACKGROUND

Quantifying changes in meniscal volume in vivo before and after partial meniscectomy (PM) could help elucidate the mechanisms involved in osteoarthritis development after meniscal injury and its surgical treatment. Purpose/

HYPOTHESIS

To determine whether quantitative magnetic resonance imaging (qMRI) can detect the immediate reduction in meniscal volume created by PM, while ruling out changes in unresected structures. We hypothesized that qMRI would be reliable for determining meniscal volume within the repeated images of unresected menisci. Additionally, we expected no significant difference in volume between the uninjured menisci of the injured knees and the same menisci of the uninjured knees.

STUDY DESIGN

Cohort study (Diagnosis); Level of evidence, 2.

METHODS

Ten subjects with meniscal tears were evaluated with 3-T MRI before and after arthroscopic PM. Manual segmentation was used to create models of the menisci and to determine the preoperative and postoperative meniscal volumes for each subject. The responsiveness and reliability of qMRI for determining meniscal volume in vivo were evaluated using these measurements. We expected a decrease in volume of the resected menisci, but not in the uninjured menisci, after surgery.

RESULTS

The mean preoperative volume of the injured menisci was significantly greater than the mean postoperative volume (2896 +/- 277 vs 2480 +/- 277 mm(3); P = .000). There was no significant difference between the mean preoperative and postoperative volumes of the uninjured menisci (2687 +/- 256 vs 2694 +/- 256 mm(3); P = 1.000).

CONCLUSION

Manual segmentation demonstrated a significant reduction in the volume of the surgically resected menisci after PM, but no significant change in the volume of unresected meniscal tissue, indicating that the manual segmentation method is responsive.

CLINICAL RELEVANCE

This approach offers a novel, reliable method to study the relationship between the volume of meniscal tissue removed during PM and subsequent patient outcomes during long-term clinical studies.

Practice patterns for combined anterior cruciate ligament and meniscal surgery in the United States

PURPOSE

The purpose of the study was to compare frequency of meniscal repair to partial meniscectomy in patients undergoing anterior cruciate ligament reconstruction using the American Board of Orthopaedic Surgeons (ABOS) database.

HYPOTHESES

(1) Practice patterns are similar with respect to geographic region. (2) Surgeons with fellowship training perform more meniscal repairs compared with general orthopaedic practitioners. (3) Younger patients are more likely to be treated with meniscal repair at the time of anterior cruciate ligament reconstruction. (4) The frequency of meniscal repair in conjunction with anterior cruciate ligament reconstruction has increased over time.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Information was extracted from the ABOS database from 2002 orthopaedic surgeons who sat for the part II examination from 2003 to 2007. The database was queried for all patients who underwent anterior cruciate ligament reconstruction (Current Procedural Terminology [CPT] code 29888) without or with meniscectomy (CPT 29881) or meniscal repair (CPT 29882). Factors affecting meniscal surgery that were investigated included patient age, geographic region of practice, fellowship training, and declared subspecialty of the surgeon.

RESULTS

On average there were 52,000 cases per year registered in the ABOS database, approximately 1700 of whom underwent anterior cruciate ligament reconstruction. Meniscal repair was most frequently performed in the Southwest region (18.6%, P < .001) and least frequently in the Northwest region (11.3%, P < .001). Combined anterior cruciate ligament reconstruction and meniscal repair was performed significantly more often by fellowship-trained surgeons (17%) than by surgeons with other fellowship training (12%) or no fellowship training (12%, P < .001) and in patients younger than age 25 years (19%) compared with those age 40 years and older (8%, P <.001). Meniscal repair was performed in 13.9% of anterior cruciate ligament reconstructions in 2003 and in 16.4% of anterior cruciate ligament reconstructions in 2007 (P > .05).

CONCLUSION

Combined anterior cruciate ligament reconstruction with meniscal repair was more frequent for younger patients and by surgeons with sports fellowship training. Concomitant meniscal repair is performed by fellowship-trained surgeons in this study in only 18% of anterior cruciate ligament reconstructions.

Strong association of MRI meniscal derangement and bone marrow lesions in knee osteoarthritis: data from the osteoarthritis initiative

INTRODUCTION

Meniscal damage is common in knee Osteoarthritis (OA) and predictive of structural progression, suggesting that their disruption plays a role in the development of OA. The bone marrow lesion (BML) is associated with pain and is a strong risk factor for structural progression. These lesions are associated with abnormal loading in a knee joint. Therefore, our hypothesis was that in those with symptomatic knee OA, large BMLs would be associated with ipsi-compartmental meniscal derangement.

METHODS

This was a cross-sectional study of a subsample of the Osteoarthritis Initiative where one set of magnetic resonance (MR) images from each participant was scored for tibiofemoral BMLs and meniscal derangement. We performed chi-squared tests comparing the prevalence of large BMLs in those with ipsi-compartmental meniscal derangement and those without.

RESULTS

160 Participants had a mean age of 61 (+/-9.9), mean BMI of 30.3 (+/-4.7) and 50% were female. 79% of medial and 39% of lateral menisci showed MRI (Magnetic Resonance Imaging) derangement. In those with medial meniscal MRI derangement, 44% had large medial BMLs while in those without medial meniscal derangement, 0% had large BMLs. Similar results were seen in the lateral compartment.

CONCLUSION

Medial and lateral MRI meniscal derangement are highly prevalent in symptomatic knee OA and BMLs are highly associated with ipsi-compartmental MRI meniscal derangement.

Imaging of knee osteoarthritis

New imaging modalities are broadening the possibilities in osteoarthritis (OA) research, and are offering new insights to help better understand the pathogenesis of this disease. Although knee radiographs are widely employed in epidemiological and clinical studies to assess structural pathology, joint radiographs provide limited outcome measures in knee OA, and other more valid, reliable and sensitive imaging modalities are now available. In particular, magnetic resonance imaging can directly visualize articular cartilage and other joint structures, such as bone and soft tissue, that are now recognized as part of the disease process. This chapter will examine imaging modalities in the assessment of knee OA, and the impact of these on our understanding of the pathogenesis of this disease.

Mood and attitude predict pain outcomes following arthroscopic knee surgery

BACKGROUND

Decreased pain represents a clinically important outcome following arthroscopic knee surgery. However, little is known about preoperative mood and attitudinal factors and their potential relationship with pain outcomes.

PURPOSE

This prospective, longitudinal study investigated the influence of preoperative depression, stress, and optimism on pain severity and interference with functioning, controlling for relevant demographic and clinical factors 1 year postoperatively.

METHODS

Participants (N = 180, mean age = 48.2 years) completed scales assessing pain severity and interference both preoperatively and postoperatively. Demographics, depression, stress, optimism, and body mass index were assessed preoperatively. Physicians assessed extent of knee osteoarthritis during surgery.

RESULTS

Hierarchical regression analyses controlling for relevant demographic and clinical variables revealed that optimism and stress were significant predictors of pain severity at 1 year but not pain interference. Extent of osteoarthritis predicted pain interference.

CONCLUSIONS

These findings support that optimism and stress are important predictors of patient-rated pain severity. They do not, however, predict the extent to which pain interferes with daily functioning.

The management of osteoarthritis: an overview and call to appropriate conservative treatment

This article presents a general outline for the management of the patient with osteoarthritis in the form of a narrative review considering diagnosis, investigation, and treatment. It is not a comprehensive discussion (subsequent articles on imaging, weight management, exercise, braces and orthotics, pharmacologic intervention, and surgery provide more detail); rather, it provides the clinician with an overview of what is available. Inevitably, there is much the interested clinician can do rather than practice nihilistic waiting. The authors encourage active clinician involvement and instilling self-management strategies in patients to further promote effective long-term treatment of this pervasive disease.

Knee injury outcomes measures

Outcomes measures have long been used in the assessment of knee injuries and management protocols. In the past decade, there has been a shift from clinician-based outcomes tools to the development and validation of patient-reported outcomes measures. General health as well as disease- and medical condition-specific outcomes measures have been so modified. The Medical Outcomes Study 36-Item Short Form is the most commonly used general health measure in orthopaedics. Joint-specific measures include the Western Ontario and McMaster Universities Osteoarthritis Index, the Knee Injury and Osteoarthritis Outcome Score, and the International Knee Documentation Committee Subjective Form. The Lysholm Knee Scale and the Cincinnati Knee Rating Scale continue to be popular, especially for the assessment of ligamentous injuries. The ACL Quality of Life score is a disease-specific, patient-reported outcomes measure of anterior cruciate ligament deficiency. The historically used Tegner activity level scale and the recently developed Marx activity level scale are used in conjunction with these outcomes measures to make possible a global assessment of recovery from knee injuries and clinician interventions.

Epidemiology of osteoarthritis

Evolving definitions of osteoarthritis and improvements in risk factor measurement that use advanced imaging, systemic and local biomarkers, and improved methods for measuring symptoms and their impact can help elucidate mechanisms and identify potential areas for intervention or prevention.

Predictors of short-term recovery differ from those of long-term outcome after arthroscopic partial meniscectomy

PURPOSE

The purpose of this study was to determine which patient clinical and demographic factors are associated with the short-term rate of recovery from arthroscopic partial meniscectomy in the year after surgery and how they differ from previously published associations with long-term outcome.

METHODS

Depth of meniscal excision, involvement of 1 or both menisci, extent of meniscal tear, and extent of osteoarthritis were determined during surgery, and age, body mass index, and gender were recorded. Mixed-model repeated-measures analyses were used longitudinally to identify independent predictors of recovery, measured by prospectively assessing knee pain, knee function, and overall physical knee status preoperatively and at regular intervals throughout postoperative recovery.

RESULTS

Neither advanced age nor increased body mass index had any influence on patient recovery over time, whereas gender was implicated, with women having significantly poorer recovery scores than men (P < .04). In addition, differences in variables indicating extent of meniscal tear and resection did not influence recovery scores over time, and the only surgical factor that impacted all 3 recovery variables was extent of osteoarthritis (P < .02).

CONCLUSIONS

We have shown that female gender and worse osteoarthritis are associated with a slower rate of short-term recovery from arthroscopic partial meniscectomy whereas age, obesity, and amount of meniscal tear/resection showed no association with rate of recovery throughout the first year postoperatively.

LEVEL OF EVIDENCE

Level I, high-quality prognostic prospective study (all patients were enrolled at the same point in their disease with more than 80% follow-up of enrolled patients).

Change in self-reported outcomes and objective physical function over 7 years in middle-aged subjects with or at high risk of knee osteoarthritis

OBJECTIVE

In the present work, we describe the clinical course and predictors of change in self-reported outcomes and objectively assessed physical function over time in middle-aged subjects at high risk of, or with knee osteoarthritis (OA).

METHODS

We examined 259 subjects (mean (SD) age 52.6 (10.4)) at mean 18 and 25 years after previous meniscectomy and 50 population-based age- and sex-matched reference subjects with the Knee injury and Osteoarthritis Outcome Score (KOOS), one-leg hop for distance and number of knee-bendings in 30 s. Radiographic OA was defined as equivalent to Kellgren and Lawrence grade 2 or worse.

RESULTS

At first assessment, meniscectomised subjects reported worse pain, function and quality of life compared with the reference group (p<0.001). They also performed fewer knee-bendings per 30 s (27 vs 31, p = 0.02). The meniscectomised patients worsened over the 4-10-year observation time in all measured outcomes (p<0.001), and to a greater extent than the reference group in pain (-5, 95% CI -10 to 0) and one-leg hop (-11, 95% CI -18 to -3). Being a woman, or having radiographic knee OA, enhanced the worsening in self-reported and objectively assessed outcomes. Older age and a higher body mass index (BMI) influenced objectively assessed physical function, but not self-reported outcomes.

CONCLUSION

Worsening over time in knee-related pain and function is greater in meniscectomised subjects compared with reference subjects. Rehabilitative efforts may be warranted in middle-aged meniscectomised patients, especially in women and those who have developed radiographic knee OA, who are at greater risk of worsening.

Meniscal damage associated with increased local subchondral bone mineral density: a Framingham study

OBJECTIVE

Because menisci and the medial vs lateral tibial plateau bone mineral density ratio (M:L BMD) are associated with loading within the knee, we postulated there to be an association between compartment-specific meniscal damage and M:L BMD. We hypothesized that knees with higher M:L BMD, consistent with increased medial subchondral BMD, would be associated with medial meniscal damage, and lower ratios with lateral meniscal damage.

METHODS

We conducted a cross-sectional study evaluating participants in the Framingham Osteoarthritis Cohort having magnetic resonance images (MRIs), BMDs, and x-rays of the knee. Medial and lateral meniscal damage were defined on MRI. We performed a logistic regression with medial meniscal damage as the outcome testing M:L BMD groups as predictor variables. We adjusted for age and sex; we used generalized estimating equations (GEE) to adjust for correlation between knees. Identical analyses were performed evaluating lateral meniscal damage.

RESULTS

When evaluating the relation of M:L BMD to medial meniscal damage, the odds ratios (ORs) of prevalent medial meniscal damage from lowest to highest quartile of M:L BMD were 1.0 (referent), 1.9, 2.4 and 8.9, P for trend <0.0001. When evaluating the relation of M:L BMD to lateral meniscal damage, the ORs of prevalent lateral meniscal damage from lowest to highest quartile of M:L BMD were 1.0 (referent), 0.3, 0.2, and 0.2, P for trend = 0.001.

CONCLUSIONS

Meniscal damage is associated with higher regional tibial BMD in the same compartment. Our findings highlight the close relationship between meniscal integrity and regional tibial subchondral BMD.

Surgical outcomes after arthroscopic partial meniscectomy

Much research has been done to determine clinical and demographic variables associated with outcomes from arthroscopic partial meniscectomy for meniscal tears. We undertook a review of the literature to determine trends regarding outcomes from this procedure. Independent variables were analyzed for associations with outcome, and outcome measures and methods of statistical analysis were reviewed. Results of these studies demonstrate that patient age and sex had no significant association with any clinical or radiographic outcome variables at 8.5, 12, and 15 years. Patients with flap tears had slower return to sports and more revisions than did those with bucket handle tears. Osteoarthritis progressed more after medial partial meniscectomy in patients older than age 40 years than in younger patients. No statistically significant difference in medial versus lateral meniscectomy overall was shown. The best radiographic results in patients who underwent medial meniscectomy occurred in valgus knees compared with varus knees. Increased Modified Outerbridge cartilage scores at the time of surgery correlated with poorer physical results at 12 years.

Porous Polymer Prosthesis for Meniscal Regeneration

Meniscus is the most commonly injured structure in the knee joint. Resection of the meniscus as well as the torn menisci is known to induce the degeneration of the articular cartilage. Replacement of the resected meniscus by allograft is limited by its availability and potential disease transmission. Artificial prostheses are being tried in an attempt to regenerate the meniscal tissue and we developed the biodegradable porous polycaprolactone(PCL) scaffold, which acts as a temporary scaffold to enable the regeneration of a new tissue in time. We report the results of rabbit implantation model. Biodegradable PCL scaffold coated with type I collagen with pores sized 100~150 +m and with compression modulus 400 kpa were fabricated by melt-molding particulate- leaching method. The molds were made using the native meniscus of the rabbit. Medial meniscus of right knee was partially removed through arthrotomy, leaving anterior 1/5 of the meniscus, after sectioning medial collateral ligament. The implant was attached to the peripheral capsule and remnant anterior meniscus with sutures. The medial meniscus of the left knee was removed and served as a control without replacement. The regenerated meniscus was harvested at 4 & 12wks after implantation. In addition to the routine histology of the tissue regenerated and remnant scaffold, junction between the normal meniscus and the regenerated tissue, and cartilage surface degeneration was observed. After 4 and 12 weeks the scaffolds, although considerable amount of the materials remained, were largely filled and covered with fibrous tissue which was assumed to be derived from synovial tissue of peripheral capsule. The tissue grossly resembling the native meniscus was maintained and spindle shaped cells with extracellular matrices were observed histologically. Neither cells with chondrocytic phenotype nor distinct cartilage matrices were observed until 12 weeks. The bonding between the regenerated tissue and the peripheral synovial capsule was firm and solid in all cases. The tissue bridges between the native meniscus and the regenerated tissue were found in 9/10 operated knees. Articular surface degeneration was not different between experimental and control groups except one case. More or less, the extrusion of the meniscus was found in almost all knees. This study revealed that meniscal replacement with PCL polymer prosthesis was feasible and led to adequate tissue formation. Long term studies on adaptive remodeling will be required.

Validity and reliability of functional performance tests in meniscectomized patients with or without knee osteoarthritis

AIMS

Reduced functional performance and muscular dysfunction after knee injury and in knee osteoarthritis (OA) is suggested to be a factor in OA development. Validated functional performance tests applicable in the clinic and large-scale studies are lacking. The aim was to study the reliability and validity of 10 functional performance tests.

METHODS

Two hundred and eighty-five subjects, 15-22 years post-meniscectomy, performed 10 functional performance tests. The mean age was 54 years (SD+/-11.2) and 79% were men; 52% had radiographic OA, and 48% were categorized as symptomatic. The tests were evaluated for test-retest reliability, discriminative ability (younger vs older age, men vs women, symptom-free vs symptomatic) and floor and ceiling effects.

RESULTS

Two of the 10 tests, maximum number of knee bendings in 30 s and one-leg hop for distance, had good test-retest reliability (ICC 0.92, 95% CI 0.86-0.96 and 0.93, 95% CI 0.87-0.97) and were able to discriminate with regard to age, gender and symptoms, and had acceptable floor effects (9% and 3%, respectively).

CONCLUSION

This study suggests the use of two functional performance tests: knee bendings/30 s and one-leg hop for distance, easy to use for evaluation of interventions due to knee injury and knee OA and when attaining long-term data of natural disease history.

Quantification of meniscal volume by segmentation of 3T magnetic resonance images

Meniscal injuries place the knee at risk for early osteoarthritis (OA) because they disrupt their load-bearing capabilities. Partial resection is routinely performed to alleviate symptomatic meniscal tears. While the removal of meniscal tissue may not be the only factor associated with partial meniscectomy outcome, the amount removed certainly contributes to functional loss. It is unknown, however, whether there is a critical amount of meniscal tissue that can be removed without diminishing the structure's chondroprotective role. In order to examine the existence of such a threshold, it is necessary to accurately quantify meniscal volume both before and after partial meniscectomy to determine the amount of meniscal tissue removed. Therefore, our goal was to develop and validate an MR-based method for assessing meniscal volume. The specific aims were: (1) to evaluate the feasibility of the MR-based segmentation method; (2) to determine the method's reliability for repeated measurements; and (3) to validate its accuracy in situ. MR images were obtained on a 3T magnet, and each scan was segmented using a biplanar approach. The MR-based volumes for each specimen were compared to those measured by water displacement. The results indicate that the biplanar approach of measuring meniscal volumes is accurate and reliable. The calculated volumes of the menisci were within 5% of the true values, the coefficients of variation were 4%, and the intraclass correlation coefficients were greater than 0.96. These data demonstrate that this method could be used to measure the amount of meniscal tissue excised during partial meniscectomy to within 125.7 mm(3).

The consequences of meniscectomy

The menisci of the knee have an important role in load-bearing and shock absorption within the joint. They may also function as secondary stabilisers, have a proprioceptive role, and aid the lubrication and nutrition of the articular cartilage. Complete or partial loss of a meniscus can have damaging effects on a knee, leading to serious long-term sequelae. This paper reviews the consequences of meniscectomy and summarises the body of evidence in the literature regarding those factors most relevant to long-term outcome.

Muscle strength, functional performance, and self-reported outcomes four years after arthroscopic partial meniscectomy in middle-aged patients

OBJECTIVE

To examine thigh muscle strength, functional performance, and self-reported outcome in patients with nontraumatic meniscus tears 4 years after operation, and to study the impact of a strength deficit on self-reported outcome and evaluate the feasibility of 3 performance tests in this patient group.

METHODS

The study group comprised 45 patients (36% women, mean age 46.7) who had an arthroscopic partial meniscectomy a mean of 4 years (range 1-6 years) previously. Main outcome measures included isokinetic strength of knee extensors and flexors, functional performance (1-leg hop, 1-leg rising, and square-hop tests), and a self-reported questionnaire (Knee Injury and Osteoarthritis Outcome Score).

RESULTS

We found lower knee extensor strength and worse 1-leg rising capacity in the operated leg, but no difference between operated and nonoperated leg for knee flexors (P < or = 0.004 and P > 0.3, respectively). Patients with a stronger quadriceps of the operated leg compared with the nonoperated leg had less pain and better function and quality of life (r = 0.4-0.6, P < or = 0.010). We found the 1-leg rising and 1-leg hop tests to be suitable performance tests in middle-aged meniscectomy patients.

CONCLUSION

Quadriceps strength is reduced in the meniscectomized leg compared with the nonoperated leg 4 years after surgery. This relative quadriceps weakness significantly affects objective and self-reported knee function, pain, and quality of life, indicating the importance of restoring muscle function after meniscectomy in middle-aged patients.

MRI and non-cartilaginous structures in knee osteoarthritis

Magnetic resonance imaging (MRI) provides a sensitive tool for examining all the structures involved in the osteoarthritis (OA) process. While much of the MRI literature previously focussed on cartilage, there is increasing research on whole-organ evaluation and including features such as synovitis, bone marrow edema, and meniscal and ligamentous pathology. The aim of this session at the Outcome Measures in Rheumatology Clinical Trials (OMERACT)-Osteoarthritis Research Society International (OARSI) Workshop for Consensus in Osteoarthritis Imaging was to describe the current MRI methods for identifying and quantifying non-cartilaginous structures and review their associations with both OA symptoms and structural progression. Although there is much experience in measuring synovitis (derived from the rheumatoid arthritis literature), only one study has reported an association of MRI-detected synovitis and effusions with OA pain. Bone marrow edema lesions, which may represent areas of trabecular remodelling, have been associated with pain and compartment-specific structural deterioration. MRI studies have confirmed the frequency and importance of meniscal damage in progressive cartilage loss, but not related such damage to symptoms. Osteophytes have been associated with cartilage loss and malalignment to the side of the osteophyte. Ligament damage, including anterior cruciate ligament tears, has been found more commonly than expected in painful OA knees. Improvements in quantitative and semi-quantitative assessments of non-cartilage features will greatly assist understanding of the OA process and its response to therapy.

Associations among preoperative MRI features and functional status following arthroscopic partial meniscectomy

BACKGROUND

Arthroscopic partial meniscectomy (APM) is the most frequently performed orthopedic procedure. Functional outcomes of APM are variable, particularly among patients with underlying knee osteoarthritis. While most patients undergoing APM have knee magnetic resonance imaging (MRI) performed preoperatively, the prognostic value of knee MRI in predicting the functional outcomes of APM has not been evaluated.

METHODS

We studied patients who had APM performed by one of five participating surgeons at one institution in 2002. The preoperative MRI scans of these patients were assessed using a standardized rating system by an independent observer who was not involved in the care of the patients and who was blinded to patient outcomes. Patients completed a questionnaire in the summer of 2003, 6-18 months postoperatively. The questionnaire included the Knee Injury and Osteoarthritis Outcome Score (KOOS) and items on satisfaction with the results of surgery. We used bivariate and multivariate techniques to evaluate the associations between MRI findings, other preoperative findings, and the functional status and pain scales of the KOOS.

RESULTS

Eighty-three patients were included in the analyses. The outcome of surgery was variable with average KOOS functional score of 77 and range of 15-100. One-quarter of patients were somewhat or very dissatisfied with the results of surgery and 17% were using a cane at the time of follow-up. In bivariate analyses, preoperative predictors of KOOS function score at follow-up included preoperative functional status and several MRI findings including the extent of cartilage damage, bone marrow edema in the medial compartment, and length of the tear. Multivariate analyses showed that after adjusting for preoperative functional status, the extent of cartilage signal abnormality in the medial compartment on MRI remained an independent predictor of functional status, 6-18 months following surgery. Specifically, preoperative functional status explained 21% of the variability in follow-up KOOS functional status score and the extent of medial tibial cartilage damage on MRI explained an additional 16%. Analyses of knee pain 1 year following APM yielded similar findings, with preoperative functional status accounting for 17% of the variability in pain scores and medial tibial cartilage damage accounting for an additional 13%.

CONCLUSIONS

Preoperative MRI findings of cartilage damage have independent prognostic value in predicting the functional outcome of APM. This study was limited by a cross-sectional design with retrospective recall of preoperative functional status. Thus, the findings need to be confirmed in prospective investigations.

Postoperative Imaging of the Knee

The knee is a frequently injured joint and, thus, a common focus of operative intervention. As operative techniques and imaging modalities evolve, radiologists must be aware of the expected postoperative appearance after knee surgeries that are performed commonly and also must be comfortable recognizing complications encountered commonly in the immediate and delayed postoperative period. Drawing on the large amount of attention this subject has received of late in the radiologic and orthopedic literature, this article reviews the knee surgeries performed most commonly and the expected normal and most frequently encountered abnormal postoperative imaging findings with an emphasis on MR imaging.

Positive effects of moderate exercise on glycosaminoglycan content in knee cartilage: a four-month, randomized, controlled trial in patients at risk of osteoarthritis

OBJECTIVE

To evaluate the effects of moderate exercise on glycosaminoglycan (GAG) content in knee cartilage in subjects at high risk of knee osteoarthritis (OA).

METHODS

Forty-five subjects (16 women, mean age 46 years, mean body mass index 26.6 kg/m(2)) who underwent partial medial meniscus resection 3-5 years previously were randomized to undergo a regimen of supervised exercise 3 times weekly for 4 months or to a nonintervention control group. Cartilage GAG content, an important aspect of the biomechanical properties of cartilage, was estimated by delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), with results expressed as the change in the T1 relaxation time in the presence of Gd-DTPA (T1[Gd]).

RESULTS

Thirty of 45 patients were examined by dGEMRIC at baseline and followup. The exercise group (n = 16) showed an improvement in the T1(Gd) compared with the control group (n = 14) (15 msec versus -15 msec; P = 0.036). To study the dose response, change in the T1(Gd) was assessed for correlation with self-reported change in physical activity level, and a strong correlation was found in the exercise group (n = 16, r(S) = 0.70, 95% confidence interval [95% CI] 0.31-0.89) and in the pooled group of all subjects (n = 30, r(S) = 0.74, 95% CI 0.52-0.87).

CONCLUSION

This in vivo cartilage monitoring study in patients at risk of knee OA who begin exercising indicates that adult human articular cartilage has a potential to adapt to loading change. Moderate exercise may be a good treatment not only to improve joint symptoms and function, but also to improve the knee cartilage GAG content in patients at high risk of developing OA.

Patellofemoral osteoarthritis coexistent with tibiofemoral osteoarthritis in a meniscectomy population

OBJECTIVES

To evaluate the frequency of patellofemoral osteoarthritis and its relevance to symptoms and function in a meniscectomy population.

METHODS

317 patients with no cruciate ligament injury were evaluated (mean (SD) age, 54 (11) years). They had undergone meniscal resection 15 to 22 years earlier (follow up rate 70%). Standing tibiofemoral and skyline patellofemoral radiographs were graded according to the OARSI atlas. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used to quantify symptoms and function. Controls were 68 unoperated subjects identified from national population records.

RESULTS

Patellofemoral osteoarthritis (isolated or coexisting with tibiofemoral osteoarthritis) was present in 66 of 317 index knees (21%) and 21 of 263 unoperated contralateral knees (8%, p<0.001). In 57/66 (86%) of these index knees, tibiofemoral osteoarthritis was present (mixed osteoarthritis). In a model adjusted for age, sex, and body mass index, the odds ratio for patellofemoral osteoarthritis (alone or in combination with tibiofemoral osteoarthritis) was 2.6 (95% confidence interval, 1.1 to 6.6) after medial meniscectomy and 5.3 (1.9 to 15.0) after lateral meniscectomy, using controls as the reference. Individuals with a mixed knee osteoarthritis pattern had more symptoms, lower function in sports and recreation, and worse knee related quality of life than subjects with isolated tibiofemoral osteoarthritis.

CONCLUSIONS

Mixed patellofemoral and tibiofemoral osteoarthritis is common in a meniscectomy population. Patellofemoral osteoarthritis is a contributing cause of knee symptoms and reduced knee related quality of life and is relevant to the management of knee complaints of this group of patients.

Six-week high-intensity exercise program for middle-aged patients with knee osteoarthritis: a randomized controlled trial [ISRCTN20244858]

Background

Studies on exercise in knee osteoarthritis (OA) have focused on elderly subjects. Subjects in this study were middle-aged with symptomatic and definite radiographic knee osteoarthritis. The aim was to test the effects of a short-term, high-intensity exercise program on self-reported pain, function and quality of life.

Methods

Patients aged 36–65, with OA grade III (Kellgren & Lawrence) were recruited. They had been referred for radiographic examination due to knee pain and had no history of major knee injury. They were randomized to a twice weekly supervised one hour exercise intervention for six weeks, or to a non-intervention control group. Exercise was performed at ≥ 60% of maximum heart rate (HR max). The primary outcome measure was the Knee injury and Osteoarthritis Outcome Score (KOOS). Follow-up occurred at 6 weeks and 6 months.

Results

Sixty-one subjects (mean age 56 (SD 6), 51 % women, mean BMI 29.5 (SD 4.8)) were randomly assigned to intervention (n = 30) or control group (n = 31). No significant differences in the KOOS subscales assessing pain, other symptoms, or function in daily life or in sport and recreation were seen at any time point between exercisers and controls. In the exercise group, an improvement was seen at 6 weeks in the KOOS subscale quality of life compared to the control group (mean change 4.0 vs. -0.7, p = 0.05). The difference between groups was still persistent at 6 months (p = 0.02).

Conclusion

A six-week high-intensive exercise program had no effect on pain or function in middle-aged patients with moderate to severe radiographic knee OA. Some effect was seen on quality of life in the exercise group compared to the control group.

Imaging the post-operative meniscus

Considerable developments have occurred in meniscal surgery, and consequently in the imaging of post-operative menisci, over the last 15 years. A drive to preserve meniscal physiologic function for as long as possible, in order to delay osteoarthrosis, has resulted in limited partial meniscectomies, meniscal repairs and meniscal transplants. Each of these techniques affects the imaging appearance of the meniscus, reducing the accuracy of conventional MRI in predicting recurrent tears. The specificity of conventional MRI can be improved by employing at least two T2-weighted sequences, but this still leaves a shortfall in sensitivity. In an attempt to increase the diagnostic accuracy of cross-sectional imaging, MR arthrography (MRA) and CT arthrography (CTA), have been applied to the post-operative meniscus. Sensitivities and specificities for these two techniques approach 90% in predicting recurrent meniscal tears. In the setting of clinical symptoms and gross meniscal deficiency, meniscal allografts are being transplanted with increasing frequency. In these transplants meniscal degeneration, fragmentation and separation are common findings, but the role of imaging in the management of these patients has not yet been well defined. This review explores the imaging techniques available for the evaluation of the post-operative meniscus, their strengths and weaknesses, and the reasons that they may find a place in a rational strategy for imaging of the symptomatic post-operative knee.

Similar group mean scores, but large individual variations, in patient-relevant outcomes over 2 years in meniscectomized subjects with and without radiographic knee osteoarthritis

BACKGROUND

Epidemiological studies have, so far, identified factors associated with increased risk for incident or progressive OA, such as age, sex, heredity, obesity, and joint injury. There is, however, a paucity of long-term data that provide information on the nature of disease progression on either group or individual levels. Such information is needed for identification of study cohorts and planning of clinical trials. The aim of the study was, thus, to assess the variation in pain and function on group and individual level over 2 years in previously meniscectomized individuals with and without radiographic knee osteoarthritis (OA).

METHODS

143 individuals (16% women, mean age at first assessment 50 years [range 27-83]) were assessed twice; approximately 14 and 16 years after isolated meniscectomy, with a median interval of 2.3 years (range 2.3-3.0). Radiographic OA (as assessed at the time of second evaluation) was present in the operated knee in 40%, and an additional 19% had a single osteophyte grade 1 in one or both of the tibiofemoral compartments. Subjects completed the self-administered and disease-specific Knee injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

There were no significant changes in the group mean KOOS subscale scores over the 2-year period. However, a great variability over time was seen within individual subjects. Out of 143 subjects, 16% improved and 12% deteriorated in the subscale Pain, and 13% improved and 14% deteriorated in the subscale ADL > or = 10 points (the suggested threshold for minimal perceptible clinical change). Similar results were seen for remaining subscales.

CONCLUSION

Group mean scores for this study cohort enriched in incipient and early-stage knee OA were similar over 2 years, but pain, function and quality of life changed considerably in individuals. These results may be valid also for other at risk groups with knee OA, and motivate further careful examination of the natural history of OA, as well as properties of the OA outcome instruments used. Longitudinal outcome data in OA studies need to be analyzed both on an individual and a group level.

Whole-Organ Magnetic Resonance Imaging Score (WORMS) of the knee in osteoarthritis

OBJECTIVES

To describe a semi-quantitative scoring method for multi-feature, whole-organ evaluation of the knee in osteoarthritis (OA) based on magnetic resonance imaging (MRI) findings. To determine the inter-observer agreement of this scoring method. To examine associations among the features included in the scoring method.

METHODS

Nineteen knees of 19 patients with knee OA were imaged with MRI using conventional pulse sequences and a clinical 1.5 T MRI system. Images were independently analyzed by two musculoskeletal radiologists using a whole-organ MRI scoring method (WORMS) that incorporated 14 features: articular cartilage integrity, subarticular bone marrow abnormality, subarticular cysts, subarticular bone attrition, marginal osteophytes, medial and lateral meniscal integrity, anterior and posterior cruciate ligament integrity, medial and lateral collateral ligament integrity, synovitis/effusion, intraarticular loose bodies, and periarticular cysts/bursitis. Intraclass correlation coefficients (ICC) were determined for each feature as a measure of inter-observer agreement. Associations among the scores for different features were expressed as Spearman Rho.

RESULTS

All knees showed structural abnormalities with MRI. Cartilage loss and osteophytes were the most prevalent features (98% and 92%, respectively). One of the least common features was ligament abnormality (8%). Inter-observer agreement for WORMS scores was high (most ICC values were >0.80). The individual features showed strong inter-associations.

CONCLUSION

The WORMS method described in this report provides multi-feature, whole-organ assessment of the knee in OA using conventional MR images, and shows high inter-observer agreement among trained readers. This method may be useful in epidemiological studies and clinical trials of OA.

Risk factors for symptomatic knee osteoarthritis fifteen to twenty-two years after meniscectomy

OBJECTIVE

To evaluate the influence of age, sex, body mass index (BMI), extent of meniscal resection, cartilage status, and knee load on the development of radiographically evident osteoarthritis (OA) of the knee and knee symptoms after meniscal resection.

METHODS

We evaluated 317 patients with no cruciate ligament injury (mean +/- SD age 54 +/- 11 years) who had undergone meniscal resection 15-22 years earlier (followup rate 70%), with radiographic and clinical examination. The Knee injury and Osteoarthritis Outcome Score was used to quantify knee-related symptoms. Sixty-eight unoperated subjects identified from national population records were included as a reference group.

RESULTS

Symptomatic radiographic OA (corresponding to Kellgren/Lawrence grade > or =2) was present in 83 of 305 operated knees (27%) and 7 of 68 control knees (10%) (relative risk 2.6, 95% confidence interval [95% CI] 1.3-6.1). Patients who had undergone total meniscectomy and subjects with obesity (BMI > or =30) had a greater likelihood of tibiofemoral radiographic OA than those who had undergone partial meniscal resection and those with a BMI <25, respectively. Furthermore, degenerative meniscal tear, intraoperative cartilage changes, and lateral meniscectomy were associated with radiographic OA more frequently than were longitudinal tear, absence of cartilage changes, and medial meniscectomy, respectively. Symptomatic tibiofemoral or patellofemoral radiographic OA was associated with obesity, female sex, and degenerative meniscal tear.

CONCLUSION

Contributing risk factors for OA development after meniscal resection are similar to risk factors for common knee OA. Systemic factors and local biomechanical factors interact. Obesity, female sex, and preexisting early-stage OA are features associated with poor self-reported and radiographic outcome. Partial meniscal resection is associated with less radiographic OA over time than is total meniscectomy.

Arthroscopic revisions in failed meniscal surgery

The aim of this study was to classify meniscal tear forms as found in 195 revision arthroscopies. Interval between primary arthroscopy and revision was 7.8+/-5.6 month. All patients were available for control after 1 year. In 174 knees the lesion was located in the medial meniscus and in 21 knees in the lateral meniscus. In the medial meniscus an unstable posterior meniscal horn was seen in 93 knees followed by incomplete horizontal tear and meniscal destruction in 37. Flap tear, circumferential tear, and failed meniscal repair were also seen. In the lateral meniscus destruction of a discoid meniscus, instability near the popliteal hiatus, and various tear forms were seen with nearly equal frequency. Postoperatively Lysholm score increased significantly in both groups. Most meniscal tears, found in revision arthroscopy, are caused by an insufficient primary operation. A diligent analysis of the tear form is absolutely necessary. An adequate radical resection technique to establish a smooth meniscal crest is indispensable.

Imaging of the disease process

Until recently, imaging evaluation of osteoarthritis (OA) has relied primarily on conventional radiography. Using radiography in clinical practice or clinical research, however, has been fraught with difficulty. Techniques for reproducibly acquiring serial radiographs of joints have improved considerably over the past several years. However, the greatest promise for advancing knowledge about OA and its treatment lies in magnetic resonance imaging (MRI) and its unique ability to examine the joint as a whole organ. In contrast to conventional radiography, MRI can directly visualize the articular cartilage, synovium, menisci, and other intra-articular structures important to the functional integrity of joints. There have been considerable advances in MRI of articular cartilage in particular over the past several years. However, much of this has come from small cross-sectional studies, and published longitudinal studies remain quite scant. The following discussion reviews the current status of imaging in OA and points to where changes might be anticipated in the future.