The Trapped Medial Meniscus Tear: An Examination Maneuver Helps Predict Arthroscopic Findings

Meniscus Tears in Elite Athletes: Treatment Considerations, Clinical Outcomes, and Return to Play

PURPOSE OF REVIEW

Management of meniscal injuries in the elite athlete is a difficult problem secondary to the high demands of athletic competition, the need for a timely return to sport, and the desire to maximize performance over time. The purpose of this review is to provide an up-to-date summary on the current literature and trends regarding the management of meniscus injuries with a special consideration for elite athletes.

RECENT FINDINGS

Historically, partial meniscectomy has been the primary treatment option for meniscus injuries. However, in recent years there has been an increased emphasis on meniscus preservation due to the increased risk of cartilage degeneration over time. Moreover, while partial meniscectomy still provides a quicker return to sport (RTS), recent literature has demonstrated similar rates of RTS and return to pre-injury levels between partial meniscectomy and meniscus repair. In the setting of symptomatic meniscal deficiency, meniscus allograft transplantation has become an increasingly utilized salvage procedure with promising yet variable outcomes on the ability to withstand elite competition. Currently, there is no uniform approach to treating meniscal injuries in elite athletes. Therefore, an individualized approach is required with consideration of the meniscus tear type, location, concomitant injuries, athlete expectations, rehabilitation timeline, and desire to prevent or delay knee osteoarthritis. In athletes with anatomically repairable tears, meniscus repair should be performed given the ability to restore native anatomy, provide high rates of RTS, and mitigate long-term chondral damage. However, partial meniscectomy can be indicated for unrepairable tears.

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.

Repair Technique for Displaced Meniscal Flap Tears Indicated by MRI Comma Sign

The meniscus comma sign has been described for displaced flap tears of the meniscus. These meniscus tears are displaced into the tibia or femoral recesses and can be often difficult to diagnose intraoperatively. We describe the technique of diagnosis and treatment of a large displaced lateral meniscus flap tear, presenting as a meniscus comma sign. The identification of the meniscus comma sign on consecutive magnetic resonance imaging (MRI) cuts suggest a flap tear of a significant size that indicates reparability. The technique would be to lift the meniscus flap from the meniscotibial recess, reduce it and then repair it with an all-inside meniscus repair or by hybrid meniscus repair techniques.

Degenerative Medial Meniscus Tear With a Displaced Flap Into the Meniscotibial Recess and Tibial Peripheral Reactive Bone Edema Presents Good Results With Arthroscopic Surgical Treatment

PURPOSE

To report the arthroscopic treatment results of a degenerative medial meniscus tear with a displaced flap into the meniscotibial recess, tibial peripheral reactive bone edema, and focal knee medial pain. As a secondary objective, we propose to identify possible factors associated with a good or poor prognosis of the surgical treatment of this lesion.

METHODS

From 2012 to 2018, patients who had this specific meniscus pathology and underwent arthroscopic surgical treatment were retrospectively evaluated. Patients with Kellgren-Lawrence (KL) classification greater than 2 were excluded. KL classification, the presence of an Outerbridge grade III/V chondral lesion of the medial compartment, limb alignment, body mass index, and smoking were evaluated. The subjective outcomes included the International Knee Documentation Committee score, improvement in the pain reported by patients, and the Global Perceived Effect (GPE) scale score.

RESULTS

A total of 69 patients were evaluated. The mean age was 58.6 ± 7.1 years. The follow-up time was 48.7 ± 20.8 months. Fifty-five (79.7%) patients reported pain improvement. The postoperative International Knee Documentation Committee was 62.6 ± 15.4, and the mean GPE was 2.3 ± 2.6. Fourteen patients (20.3%) showed no improvement in pain, and 7 patients (10.2%) presented complications. Groups that improved (GPE > 0) and did not improve (GPE < 0) did not present differences regarding age, sex, follow-up time, chondral lesions, or body mass index. Patients without improvement had a greater incidence of smoking (P = .001), varus alignment (P = .008), and more advanced KL classification (P < .001). In the multivariate analysis based on the GPE score, KL classification (P = .038) and smoking (P = .003) were significant.

CONCLUSIONS

Arthroscopic surgical treatment of degenerative medial meniscal tears with a meniscal flap displaced into the meniscotibial recess and adjacent focal bone edema in the tibia shows good results in approximately 80% of cases. Smoking and KL grade 2 were factors associated with poor prognosis of surgical treatment.

LEVEL OF EVIDENCE

Level IV (case series).

The "sleeper's sign" is valid and suggestive of a medial sub-meniscal flap tear

PURPOSE

To describe, evaluate and validate the diagnostic performance of a new clinical sign, the sleeper's sign, for the diagnosis of a medial submeniscal flap tear (MSMFT).

METHODS

This retrospective single-center series included patients aged 18-55 years old who underwent arthroscopic treatment in 2013-2015 for a medial meniscal tear. This study was performed according to STARD (standards for reporting of diagnostic accuracy) guidelines, and the reference test was a peroperative diagnosis of a MSMFT. The preoperative consultation reports were all analyzed to search for the sleeper's sign, defined as night time medial tibiofemoral pain when the patient is in the fetal position with both knees in contact and no pain during daytime activities.

RESULTS

Three-hundred and ten patients responded to the study criteria, mean age 41.7 ± 9.7 years old. The sleeper's sign was identified in 39 (12.6%) patients and a MSMFT was confirmed during arthroscopy in 47 (15.2%) cases, with significant agreement between this sign, arthroscopy (kappa = 0.78, p = 10^-4) and MR-imaging (kappa = 0.72, p < 0.0001). The performance parameters of the sleeper's sign were: sensitivity 74.5 ± 12.5%, specificity 98.5 ± 1.6%, Youden index 0.73 and accuracy 96.9%. MR imaging was found to be more sensitive (91.5 ± 8%). Multivariate analysis identified the sleeper's sign as a risk factor of MSMFT during arthroscopy: OR 131.9 CI 95% [26.9-646.2], p < 0.0001 and a bone edema next to the flap tear on MR-imaging: OR 13, CI 95% [1.9-7.1], p = 0.008.

CONCLUSION

The "sleeper's sign" is a new, valid, highly specific clinical sign for the diagnosis of a medial submeniscal flap tear. MRI was found to be more sensitive than the sleeper's sign.

LEVEL OF EVIDENCE

II.

Magnetic resonance imaging of impingement and friction syndromes around the knee

The knee is a complex joint with its function dependent on a combination of osseous and soft tissue structures. Alteration in the relationship of these tissues, due to either acute or chronic repetitive injury with possible underlying congenital predisposing factors, can result in impingement between the structures resulting in pain, particularly on activity. The purpose of this article is to provide a comprehensive review of the MRI features of various impingement syndromes around the knee.

Preoperative Diagnosis and Treatment Outcomes of Incarcerated Inferiorly Displaced Flap Tear of the Medial Meniscus: Comparison between Flap Tears with and without Incarcerated Fragment

The purpose of this study was to compare preoperative variables and postoperative outcomes between flap tears with and without incarceration of inferiorly displaced fragments of medial meniscus and find distinct features of incarcerated flap tear of medial meniscus to improve preoperative diagnosis. 79 patients who underwent partial meniscectomy for flap tear of medial meniscus were classified into two groups: group U, usual flap tear without incarcerated fragment; group I, flap tear with incarcerated inferiorly displaced fragment. Patient characteristics and preoperative variables including duration of symptom aggravation were investigated. A comprehensive physical examination including joint line tenderness was performed. Magnetic resonance imaging (MRI) examination was carried out on all patients. Clinical assessments were performed with functional scores including visual analogue scale (VAS), and radiologic evaluation was conducted. Preoperative values and postoperative outcomes measured at the minimum follow-up duration of 2 years were compared between the groups. The groups did not differ significantly regarding postoperative outcomes by functional and radiological evaluations (p > 0.05). In making preoperative diagnosis, sensitivity of diagnosis based solely on MR images was significantly lower in group I (68.8%) than that in group U (90.5%) (p = 0.040). The following clinical features differed significantly between the groups: Patients in group I had higher scores in preoperative VAS (group U = 6.6; group I = 7.7) (p = 0.011) and shorter duration of symptom aggravation (group U = 13.8 weeks; group I = 3.9 weeks) (p < 0.001). Joint line tenderness was positive more distinctly in group I (100%) than in group U (74.6%). If displaced flap tear was properly resected, improved outcomes did not differ regardless of incarceration of flap tear. In diagnosing incarcerated inferiorly displaced flap tear, sensitivity of diagnosis based solely on MR images could be low. Distinguishing clinical findings would be helpful in obtaining a more appropriate diagnosis.