Preoperative Predictors of Arthroscopic Partial Meniscectomy Outcomes: The APM Index Score.

BACKGROUND: Preoperative risk factors contributing to poor outcomes after arthroscopic partial meniscectomy (APM) have not yet been consolidated and codified into an index scoring system used to predict APM success. PURPOSE: To create an index score using available preoperative factors to predict the likelihood of favorable postoperative outcomes after APM. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A consecutive cohort of patients undergoing primary APM were enrolled in this study. Patients completed pre- and postoperative patient-reported outcome measure (PROM) questionnaires that included the Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS) for pain, Veterans RAND 12-Item Health Survey (VR-12 Physical and Mental), and Marx Activity Rating Scale (MARS). Multivariable logistic regression models were performed to evaluate independent predictors of KOOS Pain, Symptoms, and Activities of Daily Living scores and achievement of the minimal clinically important difference (MCID) and substantial clinical benefit (SCB). The authors assigned points to each variable proportional to its odds ratio, rounded to the nearest integer, to generate the index score. RESULTS: In total, 468 patients (mean age, 49 years [SD, 10.4 years; range, 19-81 years]) were included in this study. In the univariate analysis, shorter symptom duration, lower Kellgren-Lawrence (KL) grade, lower preoperative KOOS Pain value, and lower VR-12 Physical score were associated with a higher likelihood of clinical improvement at 1 year. In the multivariable model for clinical improvement with MCID, symptom duration (<3 months: OR, 3.00 [95% CI, 1.45-6.19]; 3-6 months: OR, 2.03 [95% CI, 1.10-3.72], compared with >6 months), KL grade (grade 0: OR, 3.54 [95% CI, 1.66-7.54]; grade 1: OR, 3.04 [95% CI, 1.48-6.26]; grade 2: OR, 2.31 [95% CI, 1.02-5.27], compared with grade 3), and preoperative KOOS Pain value (score <45: OR, 3.00 [95% CI, 1.57-5.76]; score of 45-60: OR, 2.80 [95% CI, 1.47-5.35], compared with score >60) were independent significant predictors for clinical improvement. The scoring algorithm demonstrated that a higher total score predicted a higher likelihood of achieving the MCID: 0 = 40%, 1 = 68%, 2 = 80%, 3 = 89%, and 4 = 96%. CONCLUSION: Using this model, the authors developed an index score that, using preoperative factors, can help identify which patients will achieve clinical improvement after APM. Longer symptom duration and higher KL grade were associated with a decreased likelihood of clinical improvement as measured by KOOS Pain at 1 year postoperatively.

Response to intra-articular cortisone injections in knee osteoarthritis patients with and without effusion on ultrasound: A pilot study.

Objective: Inflammation, manifesting as effusion and synovitis, is thought to contribute to pain in knee osteoarthritis (OA). We conducted a pilot study to investigate recruitment feasibility and assess whether effusion on ultrasound of the knee was associated with greater reduction in knee pain after corticosteroid injection. Methods: A pilot study was conducted from 2020 to 2021 including patients ≥40 years with knee OA undergoing clinically indicated corticosteroid injections. At baseline, participants completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) Pain subscale and had an ultrasound of the injected knee(s) to assess for effusion, defined as anechoic material in the suprapatellar recess. KOOS Pain was re-assessed two weeks following injection. We used mixed linear models to evaluate the change in KOOS Pain scores for knees with and without effusion to determine estimates of the magnitude of association. Results: We recruited 10 participants who contributed 16 knees from 4 clinical sessions. The mean age was 68 years (standard deviation [SD] 13) and 90% were female. Six knees had effusion. At baseline, knees without effusion had greater pain (mean KOOS Pain 44, SD 19) compared to those with effusion (mean KOOS Pain 51, SD 15). Knees without effusion had a 6 point (95% CI -16, 28) greater improvement in KOOS Pain 2-weeks post injection compared to those with effusion. Conclusion: This pilot study demonstrated clinic-based recruitment was feasible. We did not observe clinically important or statistically significant differences in pain relief post corticosteroid injection between knee OA patients with or without effusion.

The influence of meniscal pathology in the incidence of knee osteoarthritis: a review.

IMPORTANCE: Knee osteoarthritis (OA) is a common cause of pain and disability in older persons, affecting approximately 14 million individuals in the USA. Meniscal damage is also common in this age group with a prevalence of 35% in a middle-aged and older community sample and 82% in persons with evidence of radiographic knee osteoarthritis. This paper systematically reviews evidence on the association of meniscal pathology and incident radiographic knee OA. OBSERVATIONS: We included 15 articles, published between 2013 and 2021, assessing the relationship between meniscal pathology and OA incidence (Fig. 1). The menisci are crucial load-bearing structures, and the resulting increase in biomechanical stress due to meniscal damage increases the risk for OA development. While some discrepancies are present in the literature, a clinically meaningful association has been generally established between the presence of a meniscal tear or meniscal extrusion and subsequent development of incident OA. Of note, larger radial tears as well as complex and more severe tears exhibit the strongest association with the development of incident OA. The relationship between other features of meniscal morphology-such as meniscal volume and meniscal coverage-and incident OA is less clearly documented. CONCLUSIONS AND RELEVANCE: The early detection of meniscal pathology can be used to trigger preventative and therapeutic strategies designed to avert or delay knee OA in this at-risk population.

Identifying Inflammation in Knee Osteoarthritis: Relationship of Synovial Fluid White Blood Cell Count to Effusion-Synovitis on Magnetic Resonance Imaging.

OBJECTIVE: Inflammation is a potential pain generator and treatment target in knee osteoarthritis (OA). Inflammation can be detected on magnetic resonance imaging (MRI) and by synovial fluid white blood cell count (WBC). However, the performance characteristics of synovial fluid WBC for the detection of synovitis have not been established. This study was undertaken to determine the sensitivity and specificity of synovial fluid WBC in identifying inflammation in knee OA using MRI effusion-synovitis as the gold standard. METHODS: We identified records of patients seen at an academic center with a diagnosis code for knee OA, a procedural code for knee aspiration, and a laboratory order for synovial fluid WBC in the same encounter, as well as an MRI within 12 months of the aspiration. MRIs were read for effusion-synovitis using the MRI OA Knee Score (MOAKS). We dichotomized effusion-synovitis as 1) none or small, or 2) medium or large. We calculated the sensitivity and specificity of synovial fluid WBC using MRI effusion-synovitis (medium/large) as the gold standard. We used the Youden index to identify the best cut point. RESULTS: We included 75 patients. Mean ± SD age was 63 ± 12 years, and 69% were female. The synovial fluid WBC was higher in the medium/large effusion-synovitis group (median 335 [interquartile range (IQR) 312]) than in the none/small group (median 194 [IQR 272]). The optimal cut point was 242, yielding a sensitivity of 71% (95% confidence interval [95% CI] 56-83%) and specificity of 63% (95% CI 41-81%). CONCLUSION: The sensitivity and specificity of synovial fluid WBC in identifying effusion-synovitis on MRI were limited. Further research is needed to better understand the association between MRI and effusion-synovitis measured by synovial fluid and to determine which measure more strongly relates to synovial histopathology and patient outcomes.

Diagnosis and Management of Lumbar Spinal Stenosis: A Review.

Importance: Lumbar spinal stenosis is a prevalent and disabling cause of low back and leg pain in older persons, affecting an estimated 103 million persons worldwide. Most are treated nonoperatively. Approximately 600 000 surgical procedures are performed in the US each year for lumbar spinal stenosis. Observations: The prevalence of the clinical syndrome of lumbar spinal stenosis in US adults is approximately 11% and increases with age. The diagnosis can generally be made based on a clinical history of back and lower extremity pain that is provoked by lumbar extension, relieved by lumbar flexion, and confirmed with cross-sectional imaging, such as computed tomography or magnetic resonance imaging (MRI). Nonoperative treatment includes activity modification such as reducing periods of standing or walking, oral medications to diminish pain such as nonsteroidal anti-inflammatory drugs (NSAIDs), and physical therapy. In a series of patients with lumbar spinal stenosis followed up for up to 3 years without operative intervention, approximately one-third of patients reported improvement, approximately 50% reported no change in symptoms, and approximately 10% to 20% of patients reported that their back pain, leg pain, and walking were worse. Long-term benefits of epidural steroid injections for lumbar spinal stenosis have not been demonstrated. Surgery appears effective in carefully selected patients with back, buttock, and lower extremity pain who do not improve with conservative management. For example, in a randomized trial of 94 participants with symptomatic and radiographic degenerative lumbar spinal stenosis, decompressive laminectomy improved symptoms more than nonoperative therapy (difference, 7.8 points; 95% CI, 0.8-14.9; minimum clinically important difference, 10-12.8) on the Oswestry Disability Index (score range, 0-100). Among persons with lumbar spinal stenosis and concomitant spondylolisthesis, lumbar fusion increased symptom resolution in 1 trial (difference, 5.7 points; 95% CI, 0.1 to 11.3) on the 36-Item Short Form Health Survey physical dimension score (range, 0-100), but 2 other trials showed either no important differences between the 2 therapies or noninferiority of lumbar decompression alone compared with lumbar decompression plus spinal fusion (MCID, 2-4.9 points). In a noninferiority trial, 71.4% treated with lumbar decompression alone vs 72.9% of those receiving decompression plus fusion achieved a 30% or more reduction in Oswestry Disability Index score, consistent with the prespecified noninferiority hypothesis. Fusion is associated with greater risk of complications such as blood loss, infection, longer hospital stays, and higher costs. Thus, the precise indications for concomitant lumbar fusion in persons with lumbar spinal stenosis and spondylolisthesis remain unclear. Conclusions and Relevance: Lumbar spinal stenosis affects approximately 103 million people worldwide and 11% of older adults in the US. First-line therapy is activity modification, analgesia, and physical therapy. Long-term benefits from epidural steroid injections have not been established. Selected patients with continued pain and activity limitation may be candidates for decompressive surgery.