Magnetic resonance imaging of the postoperative meniscus

Greater Rotational Knee Laxity Observed at Second-Look Arthroscopy in Patients With Failed Meniscal Repair Performed at the Time of Anterior Cruciate Ligament Reconstruction

PURPOSE

To evaluate the healing of meniscal repair performed concomitantly with anterior cruciate ligament reconstruction (ACLR) using second-look arthroscopy, as well as the relationship between meniscal healing and knee laxity using quantitative evaluation under anesthesia.

METHODS

This retrospective study included patients who underwent primary double-bundle ACLR with meniscal repair between June 2016 and June 2021, with a 2-year minimum follow-up. Meniscal healing was evaluated by second-look arthroscopy at least 1 year postoperatively, and knee laxity was measured under general anesthesia preoperatively, intraoperatively, and at second-look arthroscopy.

RESULTS

Of 562 knees treated with ACLR, 113 knees, with 137 meniscal repairs, were analyzed. Second-look arthroscopy classified 114 menisci (83.2%) as healed and 23 (16.8%) as failed. The side-to-side difference in anterior tibial translation (ATT) and the side-to-side ratios of tibial acceleration and external rotational angular velocity (ERAV) improved intraoperatively in both groups (ATT, 6.0 to -1.0 mm [P < .001] and 6.0 to -1.0 mm [P < .001]; acceleration, 5.1 to 1.2 and 4.9 to 1.1 [P < .001]; ERAV, 3.6 to 1.3 and 3.6 to 1.6 [P < .001]). There were no significant differences in ATT and patient-reported outcome measures, including the Lysholm score and Knee Injury and Osteoarthritis Outcome Score (KOOS), between the groups. The proportion of patients achieving the minimal clinically important difference for the Lysholm score and KOOS did not differ significantly between the groups. However, at 1 year postoperatively, acceleration and ERAV were higher in the failed group than in the healed group (P < .001).

CONCLUSIONS

Patients with failure of meniscal repair performed concomitantly with ACLR showed significantly greater rotational knee laxity at the time of second-look arthroscopy. These patients exhibited significantly higher preoperative and postoperative pivot-shift grades than those who did not experience failure of meniscal repair. There were no significant differences in ATT and patient-reported outcome measures between the groups.

LEVEL OF EVIDENCE

Level Ⅲ, retrospective comparative study.

Differences in Graft Tear Configurations in Medial and Lateral Meniscal Allograft Transplantation: Objective Evaluations Using Magnetic Resonance Imaging

BACKGROUND

Few studies have compared the characteristics of meniscal allograft tears between medial and lateral meniscal allograft transplantation (MAT) using bone fixation.

PURPOSE

To investigate the prevalence, location, and patterns of allograft tears after MAT with the bone fixation technique and compare tear patterns between medial and lateral compartments according to the time elapsed after surgery.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The charts of consecutive patients who underwent primary medial or lateral MAT between December 1996 and June 2019 were retrospectively reviewed. The location, pattern, and postoperative periods during which allograft tears occurred were evaluated by reviewing all series of follow-up magnetic resonance imaging (MRI) scans, which were performed at 6 weeks, 3 months, 6 months, and 1 year postoperatively and every 2 years thereafter with the patient's agreement. Postoperative periods for allograft tears were defined as the time between surgery and the follow-up MRI scan in which the meniscal tear was first confirmed. Allograft tears were compared between the medial and lateral MAT groups.

RESULTS

A total of 327 consecutive patients who underwent MAT (55 medial, 272 lateral) with a minimum 2-year follow-up were retrospectively reviewed. The incidences of allograft tears after medial and lateral MATs were 32.7% and 30.9%, respectively. The mean times for tears were 80.1 ± 81.1 months and 48.9 ± 46.3 months in the medial and lateral MAT groups, respectively (P = .130). In both the medial and lateral MAT groups, allograft tears were observed mainly in the posterior horn, with complex tears being the most commonly identified tear type. In medial MATs, root tears were the second most common at 27.8%, with a significantly higher proportion than the lateral MATs (P = .014). On the other hand, in lateral MATs, meniscocapsular separation and radial tears were the second most common at 15.5% each, albeit not significantly more common than in medial MATs (P = .123 and P = .454, respectively). All root tears in medial MATs and meniscocapsular separations in lateral MATs were observed within 1 year postoperatively.

CONCLUSION

Significant differences in allograft tear patterns were identified between the medial and lateral MAT groups. The proportion of root tears in medial MATs was higher than that in lateral MATs; conversely, the proportion of meniscocapsular separation was more common in lateral MATs. Such tear patterns, which may require surgical repair or graft resection, were observed only within 1 year of surgery. Therefore, close observation and regular follow-up in the earlier postoperative period are necessary after medial or lateral MATs.

Do MRI Results Represent Functional Outcomes Following Arthroscopic Repair of an Isolated Meniscus Tear in Young Patients?-A Prospective Comparative Cohort Study

BACKGROUND

The use of postoperative MRI to assess the healing status of repaired menisci is a long-standing issue. This study evaluates and compares functional and MRI outcomes following an arthroscopic meniscus repair procedure with the aim of postoperative MRI diagnostic accuracy clarification in young patients.

METHODS

A total of 35 patients under 18 years old who underwent isolated meniscus repair were included. The Pedi-IKDC score, Lysholm score, and Tegner activity index (TAS) were compared between the groups formed according to the Stroller and Crues three-grade classification of postoperative MRI-based evaluations. Grade 3 MRI views were classified as unhealed, grade 2 as partially healed, and grade 1 as fully healed within the repaired meniscus, whereas grade 3 cases were considered unsuccessful due to MRI evaluation.

RESULTS

MRI assessment revealed 4 cases of grade 1 (11.4%), 14 cases of grade 2 (40.8%), and 17 cases of grade 3 (48.0%) lesions. Pedi-IKDC and TAS scores were significantly higher among MRI grade 2 patients than among MRI grade 3 patients (p < 0.05). Weak negative correlations between MRI grades and all functional scales were found (p < 0.05). ROC analysis showed that Pedi-IKDC and TAS scores could correctly classify 77% and 71% of MRI grade 3 patients, respectively. The optimal cut-off values to detect grade 3 patients were 88.74 for the Pedi-IKDC score and 4.5 for the TAS score.

CONCLUSIONS

To conclude, established functional score cut-off values may help identify unhealed meniscus repair patients.

Repairing Complete Radial Tears of the Lateral Meniscus: Arthroscopic All-Inside Double Vertical Cross-Suture Technique Is Effective and Safe With 2-Year Minimum Follow-Up

PURPOSE

To assess the failure rate and clinical outcomes of the all-inside, double-vertical, cross-suture technique in repairing complete radial tears of the lateral meniscus.

METHOD

We retrospectively reviewed records of patients with this injury on whom the present technique was employed at our institution between 2011 and 2018, with at least 24 months of follow-up. Six months postoperatively, the meniscus healing and extrusion status were evaluated through magnetic resonance imaging. Preoperative and postoperative knee function, measured through IKDC, Lysholm knee, and Tegner activity scale scores, were compared.

RESULTS

In total, 27 patients underwent the procedure. The preoperative mean (standard deviation) IKDC score, Lysholm knee score, and Tegner activity scale scores were 53.4 ± 5.3, 63.2 ± 9.3, and 4 ± .7, respectively. At the last follow-up (≥24 months postoperatively), these scores increased to 92.1 ± 2.6, 90.8 ± 4.2, and 6.1 ± 1.3, respectively (all P < .05). Complete healing of the meniscus was observed in 23 patients, and 4 patients had meniscus retear or nonhealing. The overall retear or nonhealing rate was 14.8%. Healing rates between those with isolated radial tears (87.5%) and those with combined anterior cruciate ligament rupture (84.2%; P = .826) were comparable. No difference was observed in the progression of coronal and sagittal meniscus extrusion (P = .133 and .797, respectively).

CONCLUSION

In patients with complete radial tears of the lateral meniscus, the arthroscopic all-inside double vertical cross-suture repair technique resulted in an 85.2% healing rate, improvements in functional outcomes and activity levels, and no identifiable progression of meniscus extrusion. The all-inside double vertical cross-suture technique is effective and safe for the repair of radial tears of the meniscus.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

In-Office Needle Arthroscopy Can Evaluate Meniscus Tear Repair Healing as an Alternative to Magnetic Resonance Imaging

PURPOSE

To assess the healing of horizontal cleavage tears of the meniscus 1 year after surgical repair and to determine what modality is best to determine healing.

METHODS

Patients were prospectively followed for 12 months after surgical meniscus repair using a circumferential compression stitch. Inclusion criteria were preoperative magnetic resonance imaging (MRI) evidence of horizontal cleavage tear, age between 18 and 50 years, and no concomitant anterior cruciate ligament reconstruction. Patients were excluded if they were >50 years old, had a meniscus tear pattern other than horizontal cleavage tear, and underwent concomitant ligament reconstruction. MRIs were performed 1-year postoperatively for evaluation of repair healing. Preoperative and postoperative MRIs of tears were evaluated blindly by a musculoskeletal radiologist. In-office needle arthroscopy was performed at 6 months post-operatively.

RESULTS

Eight patients were included and had surgery between March 2016 and November 2017. There were 4 medial and 4 lateral meniscus tears. No patients had recurrence of preoperative symptoms or evidence of retear. Six repairs evaluated by in-office needle (at 5.9 months postsurgery) arthroscopy demonstrated complete healing. Seven of the 8 patients had grade III changes on preoperative MRI, and 1 patient had grade IIc changes. On postoperative MRI, 5 of 7 patients had grade III changes, 1 patient had IIc changes, and 1 had IIb changes. There was no significant difference in the proportion of patients with grade III changes preoperatively compared with postoperatively (P = .57). One of 8 patients with preoperative MRIs demonstrated extrusion where no patients demonstrate postoperative MRI evidence of extrusion (P = .47).

CONCLUSIONS

Horizontal cleavage meniscal tears repaired with a circumferential compression stitch demonstrate healing on in-office needle arthroscopy 6 months after surgery. No evidence of incomplete or failed healing was found. MRI at 1 year after surgery demonstrated residual tear evidence for all patients.

LEVEL OF EVIDENCE

IV, therapeutic case series.

Clinical and Radiological Outcomes After Isolated Anterior Horn Repair of Medial and Lateral Meniscus at 24 Months' Follow-up, With the Outside-In Technique

Background

The effects of repair of isolated anterior horn meniscus lesions have not been thoroughly described in the literature. We aimed to evaluate outcomes with subjective clinical scores and imaging modalities after repair of isolated anterior horn tears, at 24 months’ follow-up.

Methods

Records of all patients that opted for surgical repair of isolated, anterior horn tears of the medial and lateral meniscus were retrospectively reviewed, between 2016 and 2018. All patients were treated with arthroscopic outside-in technique by the same surgeon. Preoperative and postoperative clinical files were accessed to recover records of preoperative symptomatology, patient-reported scores [International Knee Documentation Committee (IKDC) rating, Lysholm score and Tegner activity level], preoperative and postoperative MRI data and time from injury to surgery.

Results

Mean age of eight patients was 25.25 years (range 18-37 years). Diagnostic preoperative MRI revealed isolated anterior horn tear of the lateral meniscus and medial meniscus in five patients and an isolated anterior horn tear of the medial meniscus in three patients. Mean time from injury to surgical repair was 23.75 days (range 7-43). We considered seven out of eight repairs to be successfully healed. At 24 months’ follow-up: Mean Lysholm score was 92.25 (range 89-95), Tegner activity scale score was 6.5 (range 5-8) and IKDC score was 91.78 (range 87.8-94.4). All scores significantly improved compared to preoperative values (p<0.001).

Conclusions

Outside-in is a reliable technique to repair meniscal anterior horn tears, both medially and laterally, with high healing rates and patient satisfaction in young, active patients.

Increased MRI Signal Intensity of Allografts in the Midterm Period After Meniscal Allograft Transplant: An Evaluation of Clinical Significance According to Location and Morphology

Background:

Magnetic resonance imaging (MRI) is an effective tool for objective evaluation after meniscal allograft transplant (MAT). Little is known about the association between MRI features of allograft and clinical outcomes.

Purpose/Hypothesis:

To assess the degree and location of signal intensity (SI) as well as the morphology of allografts on MRI after MAT and evaluate the association between clinical outcomes and MRI features in the midterm period. It was hypothesized that a high SI accompanied by a deformed allograft in specific locations on MRI would be associated with inferior clinical outcomes.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Included were patients who underwent MAT with fresh-frozen allografts and had >3 years of follow-up with 3.0-T MRI scans. Allograft status was assessed by SI on MRI as grade 0 (normal), grade 1 (globular increased SI not adjacent to the articular surface), grade 2 (linear SI within the meniscus), or grade 3 (increased SI extended to the articular surface). Allograft morphology was assessed by the presence of distorted contours. Clinical outcomes were evaluated using the Lysholm score. The association between clinical outcomes and MRI findings was assessed by multiple linear regression analysis.

Results:

A total of 138 patients (156 MAT procedures: 132 lateral, 24 medial) with a mean follow-up period of 55.4 ± 19.9 months (range, 36-110 months) were enrolled in this study. Grade 3 SI was observed in the posterior meniscus root and posterior third of the allograft in 39 (25%) and 62 (39.7%) MATs, respectively. Among the 62 MATs with grade 3 SI in the posterior third of the allograft, 34 (54.8%) were accompanied by distorted allograft contour. The presence of grade 3 SI with distorted contour in the posterior third of the allograft was significantly associated with inferior outcomes (β = –6.5 [95% CI, –12.5 to –0.5]; P < .035), as was the presence of grade 3 SI in the posterior meniscus root (β = –5.5 [95% CI, –10.5 to –0.4]; P < .034).

Conclusion:

On MRI evaluation in the midterm period after MAT, grade 3 SIs of the meniscal allograft were observed in about a third of the cases, and the association with clinical outcomes was dependent on the specific location and morphology of the allograft on MRI.

Management of traumatic meniscus tears: the 2019 ESSKA meniscus consensus

PURPOSE

The importance of meniscus integrity in the prevention of early osteoarthritis is well known, and preservation is accepted as the primary goal. The purpose of the ESSKA (European Society for Sports Traumatology, Knee Surgery and Arthroscopy) European consensus on traumatic meniscus tears was to provide recommendations for the treatment of meniscus tears based on both scientific evidence and the clinical experience of knee experts.

METHODS

Three groups of surgeons and scientists elaborated and ratified the so-called formal consensus process to define the recommendations for the management of traumatic meniscus tears. A traumatic meniscus tear was defined as a tear with an acute onset of symptoms caused by a sufficient trauma. The expert groups included a steering group of eight European surgeons and scientists, a rating group of another nineteen European surgeons, and a peer review group. The steering group prepared twenty-seven question and answer sets based on the scientific literature. The quality of the answers received grades of A (a high level of scientific support), B (scientific presumption), C (a low level of scientific support) or D (expert opinion). These question and answer sets were then submitted to and evaluated by the rating group. All answers were scored from 1 (= totally inappropriate) to 9 (= totally appropriate) points. Thereafter, the comments of the members of the rating group were incorporated by the steering group and the consensus was submitted to the rating group a second time. Once a general consensus was reached between the steering and rating groups, the finalized question and answer sets were submitted for final review by the peer review group composed of representatives of the ESSKA-affiliated national societies. Eighteen representatives replied.

RESULTS

The review of the literature revealed a rather low scientific quality of studies examining the treatment of traumatic meniscus tears. Of the 27 questions, only one question received a grade of A (a high level of scientific support), and another received a grade of B (scientific presumption). The remaining questions received grades of C and D. The mean rating of all questions by the rating group was 8.2 (95% confidence interval 8.1-8.4). A general agreement that MRI should be performed on a systematic basis was not achieved. However, MRI was recommended when arthroscopy would be considered to identify concomitant pathologies. In this case, the indication for MRI should be determined by a musculoskeletal specialist. Based on our data, stable left in situ lateral meniscus tears appear to show a better prognosis than medial tears. When repair is required, surgery should be performed as early as possible. Evidence that biological enhancement such as needling or the application of platelet-rich plasma would improve healing was not identified. Preservation of the meniscus should be considered as the first line of treatment because of an inferior clinical and radiological long-term outcome after partial meniscectomy compared to meniscus repair.

DISCUSSION

The consensus was generated to present the best possible recommendations for the treatment of traumatic meniscus tears and provides some groundwork for a clinical decision-making process regarding the treatment of meniscus tears. Preservation of the meniscus should be the first line of treatment when possible, because the clinical and radiological long-term outcomes are worse after partial meniscectomy than after meniscus preservation. The consensus clearly states that numerous meniscus tears that were considered irreparable should be repaired, e.g., older tears, tears in obese patients, long tears, etc. LEVEL OF EVIDENCE: II.

Outcomes More Than 2 Years After Meniscal Repair for Radial/Flap Tears of the Posterior Lateral Meniscus Combined With Anterior Cruciate Ligament Reconstruction

BACKGROUND

Meniscal function after repair of radial/flap tears of the posterior horn of the lateral meniscus (LM) with anterior cruciate ligament reconstruction (ACLR) has not been comprehensively investigated.

PURPOSE

To evaluate not only the clinical and radiographic outcomes of patients with repair of radial/flap tears of the posterior LM with ACLR but also the healing status of the repaired meniscus and changes of chondral status with second-look arthroscopy.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From January 2008 to April 2016, 41 patients of a consecutive series of 505 primary anatomic ACLR cases had a concomitant radial/flap tear of the posterior horn of the LM and underwent side-to-side repair with an inside-out or all-inside technique. All patients were followed for >2 years, evaluated clinically and radiologically (radiograph and magnetic resonance imaging [MRI]), and compared with a control group without any concomitant injuries that underwent ACLR. Of the 41 patients, 30 were assessed by second-look arthroscopy 2 years postoperatively.

RESULTS

The mean follow-up times of the study and control groups were 3.4 and 3.9 years, respectively. The study group showed no significant differences in clinical findings, lateral joint space narrowing on radiograph, and coronal extrusion on MRI as compared with the control group, whereas sagittal extrusion on MRI progressed significantly in the study group (1.2 ± 1.5 mm vs 0.32 ± 1.0 mm, P < .001). Eighteen patients (60%) obtained complete healing; 9 (30%) showed partial healing; and 3 (10%) failed to heal on second-look arthroscopy. Changes of chondral status in the femoral condyle showed no significant difference between the groups (P = .29). However, chondral status of the lateral tibial plateau worsened significantly in the study group (P = .0011).

CONCLUSION

The clinical and radiographic outcomes after repair of radial/flap tears of the posterior horn of the LM as combined with anatomic ACLR were successful and comparable with those after isolated ACLR without any other injuries at a mean postoperative follow-up of 3.4 years, except for sagittal extrusion on MRI. Chondral lesions of the lateral tibial plateau deteriorated regardless of meniscal healing at 2 years postoperatively. Surgeons should keep in mind that chondral injuries might progress over the midterm.

Second-Look Arthroscopic Evaluations of Meniscal Repairs Associated With Anterior Cruciate Ligament Reconstruction

PURPOSE

To examine the healing status of meniscal repair performed concomitantly with anterior cruciate ligament (ACL) reconstruction with our current indication and surgical procedure based on second-look arthroscopic results. Additionally, the significance of the demographic and clinical factors that can potentially influence the healing rate was statistically assessed.

METHODS

Between January 2009 and January 2015, second-look was performed for patients who opted to have tibial screw removal and agreed to have concomitant arthroscopy. The healing status of the repaired meniscus was classified into 3 conditions: healed, incompletely healed, and not healed. In addition, clinical outcomes were evaluated at a minimal 1-year follow-up. The effects of patient factors on the meniscal healing rate were statistically assessed.

RESULTS

A total of 217 knees underwent arthroscopic meniscal repair concomitant with ACL reconstruction, while second-look was performed for 105 knees. The average period from index surgery to second-look was 15.0 months. Clinical evaluation was conducted at a mean of 17 months (12-50 months). Based on the second-look arthroscopic findings, 64 menisci, 22 menisci, and 29 menisci were categorized as healed, incompletely healed, and not healed, respectively. When the not healed condition was defined as failed repair, a Tegner activity score of 8 or more, recurrent instability, tears in the red-white to white-white zones, and time from injury to surgery of 4 months or longer were identified as clinical factors significantly correlated with failure (P < .01).

CONCLUSIONS

Meniscal repair in ACL reconstructed knees with expanded indications achieved a healing rate (including incomplete healing) of 75%. Clinical factors such as high sports activity level, recurrent ACL instability, poor vascularity of the repaired site, and long duration from injury to surgery were shown to impair the healing status.

LEVEL OF EVIDENCE

Level Ⅳ, therapeutic study, case series.

Using only MRI is moderately reliable in the prediction of meniscal tear reparability

PURPOSE

The purpose of this study was to evaluate the role of surgeons' experience with meniscal repairs and meniscectomy decisions, and to determine the factors affecting the disagreement between meniscal repairs and meniscectomy decisions.

METHODS

In total, 223 patients with meniscal tears, 106 meniscal repairs, and 117 meniscectomies were included. Six orthopedic surgeons (3: > 5 years; 3: < 5 years' arthroscopy experience) were blinded, and they independently reviewed all preoperative MR images for over a month. Their reviews were compared with arthroscopic interventions performed by a surgeon with > 10 years' arthroscopy experience. Reparability-associated factors were also evaluated using multivariate logistic regression.

RESULTS

The first and second evaluation results did not differ significantly between groups (n.s.). There was good agreement between MRI predictions and arthroscopic interventions for both groups (< 5 years' experience: k = 0.248, agreement 62.3%; > 5 years' experience: k = 0.351, agreement 67.3%). Sex, side, and distance of tear from the meniscocapsular junction were not significantly different between agreements and disagreements. Disagreement regarding meniscectomy was significantly higher than those regarding meniscus repair (p = 0.002). Concomitant anterior cruciate ligament (ACL) injury, osteochondral lesions, and medial meniscal tear increased the likelihood of meniscal repair (p = 0.0063, p = 0.0010, and p = 0.0369, respectively). An increased risk of disagreement between MRI and surgical procedure was found in the presence of bucket-handle, horizontal or complex tear, chronic tear, high sports activity and expectation level.

CONCLUSION

Surgeon's experience level may influence the prediction of meniscus reparability. Concomitant ACL injury, osteochondral lesions, and presence of medial meniscal tear increase the likelihood of meniscal repair. Tear type, tear chronicity, patient's activity and expectation level may influence the surgeon's operative decision in addition to MRI.

LEVEL OF EVIDENCE

III.

Introduction of an MR-based semi-quantitative score for assessing partial meniscectomy and relation to knee joint degenerative disease: data from the Osteoarthritis Initiative

OBJECTIVES

To develop an MR-based semi-quantitative meniscus scoring technique for postoperative assessment of the degree of meniscal resection, to test its reproducibility, and to study the relationship between the amount of resection and degenerative disease burden.

METHODS

We studied the right knee of 135 participants from the Osteoarthritis Initiative that underwent meniscal surgery an average of 14 years previously. The amount of meniscal resection was assessed on baseline 3.0-T MRIs and calculated as meniscus resection score (MenRS) with a range of 0 to 18. Knee abnormalities at baseline and 48 months were graded using a modified Whole-Organ Magnetic Resonance Imaging Score (WORMS). Subjects were also stratified according to meniscal resection performed after injury versus without preceding injury. Statistical analysis included intra-class correlation coefficient (ICC) to determine reproducibility as well as regression models and partial correlations to correlate MenRS with WORMS outcomes.

RESULTS

ICC values for intra- and inter-observer reproducibility of MenRS were 0.980 and 0.977, respectively. Overall, the amount of meniscal resection showed a significant correlation with baseline WORMS grades: higher MenRS was associated with higher total WORMS grades (p = 0.004) and cartilage (p = 0.004) and ligament (p < 0.001) subscores. However, no significant association between MenRS and change in WORMS grades over 48 months was found. The relationship between MenRS and baseline WORMS grades did not change after adjusting for a reported history of knee injury.

CONCLUSIONS

Postoperative assessment of the knee following partial meniscectomy using the newly developed MenRS showed excellent reproducibility and significant cross-sectional correlation with WORMS gradings.

KEY POINTS

• The newly developed semi-quantitative MR-based meniscal resection score demonstrated excellent reproducibility. • A significant correlation between the amount of meniscal resection measured using the newly developed score and the degree of overall knee joint degenerative disease and cartilage defects was found.

Second look arthroscopic evaluation of repaired radial/oblique tears of the midbody of the lateral meniscus in stable knees

BACKGROUND

Radial/oblique tears of the midbody of the lateral meniscus significantly impair the ability of the meniscus to withstand the tibiofemoral load, requiring meniscal repair. However, healing status after meniscal repair has not been fully elucidated. This study aimed to evaluate arthroscopic findings after inside-out suture repair for isolated radial/oblique tears of the midbody of the lateral meniscus.

METHODS

From 2011 to 2015, 18 consecutive patients with isolated radial/oblique tears of the midbody of the lateral meniscus underwent arthroscopic inside-out repair with the tie-grip suture technique. All knees were stable with no previous surgery. All patients were evaluated by second-look arthroscopy at six months postoperatively. Activities including jogging were not allowed until meniscal status was evaluated arthroscopically. To analyze factors associated with healing rates, age, time from injury to initial surgery, and tear zone were compared.

RESULTS

Second-look arthroscopy revealed complete healing in four (22%) patients, partial healing in seven (39%), and failure to heal in seven (39%). Significant differences were observed for tear zone (p < 0.0001), but not for age and timing of repair.

CONCLUSIONS

Arthroscopic evaluation revealed that inside-out repair with the tie-grip suture technique for isolated radial/oblique tears of the midbody of the lateral meniscus achieved complete or partial healing only in 61% of patients. Satisfactory results were observed particularly in patients with tears extending to the vascular zone, whereas those with tears in the avascular zone failed to achieve healing. Therefore, the operative indication of inside-out repair for radial/oblique tears of the midbody of the lateral meniscus might be limited to tears extending into the vascular zone. Given that 39% of cases were arthroscopically considered a failure even if patients complained of no symptoms in daily life, decisions should be made carefully to allow patients to return to sports activities.

Platelet-rich plasma for open meniscal repair in young patients: any benefit?

PURPOSE

Many studies have demonstrated that injection of various growth factors including platelet-derived growth factor could increase meniscal cell activity and stimulate repair. The purpose of this study was to augment repair and promote meniscal healing by the use of platelet-rich plasma (PRP) within horizontal cleavage meniscal tears repaired via an open approach. The hypothesis was that the clinical outcomes and healing process would be improved using this meniscal healing augmentation technique.

METHODS

In this case-control study, 34 consecutive young patients underwent an open meniscal repair to treat symptomatic Grade 2 or Grade 3 horizontal meniscal tears [median age 28 years (13-40)]. The median time between the onset of symptoms and surgery was 11.5 months (6-50). In the first group (17 consecutive patients, Group 1), a standard open meniscal repair was performed. In the second group (17 consecutive patients, Group 2), the same surgical repair was performed, but platelet-rich plasma was introduced into the lesion at the end of the procedure. Clinical outcomes were evaluated using KOOS and IKDC 2000 scores. MRI was performed at 1 year after surgery for objective evaluation.

RESULTS

At a minimum of 24 months postoperatively (mean 32.2 months, 24-40), three patients underwent subsequent meniscectomy (two in Group 1, one in Group 2). The mean KOOS distribution (pain, symptoms, daily activities, sports, quality of life) was 78.4, 86.1, 93.8, 74.4, 74.6 in Group 1, and 93.3, 90.7, 97.1, 88.8, 78.3 in Group 2 (p < 0.05 for pain and sports parameters). MRI revealed five cases with the complete disappearance of any hypersignal within the repaired meniscus in Group 2, and none in Group 1 (p < 0.01).

CONCLUSIONS

Open meniscal repair of horizontal tears extending into the avascular zone was effective at midterm follow-up in young patients. Clinical outcomes were slightly improved by the addition of PRP in this case-control study.

LEVEL OF EVIDENCE

III.

The Effect of Perioperative Ketorolac on the Clinical Failure Rate of Meniscal Repair

Background:

There has been recent interest in the effect of nonsteroidal anti-inflammatory medications on musculoskeletal healing. No studies have yet addressed the effect of these medications on meniscal healing.

Hypothesis:

The administration of ketorolac in the perioperative period will result in higher rates of meniscal repair clinical failure.

Study design:

Cohort study; Level of evidence, 3.

Methods:

A total of 110 consecutive patients underwent meniscal repair at our institution between August 1998 and July 2001. Three patients were lost to follow-up, and the remaining 107 (mean age, 15.9 ± 4.4 years) had a minimum 5-year follow-up (mean follow-up, 5.5 years). Thirty-two patients (30%) received ketorolac perioperatively. The primary outcome measure was reoperation for continued symptoms of meniscal pathology. Asymptomatic patients were evaluated by the International Knee Documentation Committee (IKDC) Subjective Knee Form, Short Form–36 (SF-36) Health Survey, and Knee Outcome Osteoarthritis Score (KOOS).

Results:

Kaplan-Meier survivorship revealed no difference in reoperation rates with and without the administration of perioperative ketorolac (P = .95). There was an overall failure rate of 35% (37/107 patients), with a 34% failure rate in patients receiving ketorolac (11/32 patients). Multivariable Cox regression confirmed that age, duration of symptoms, meniscal tear type, fixation technique, concurrent anterior cruciate ligament repair, and ketorolac usage did not have an impact on the rate of failure (P > .05 for all; ketorolac use, P > .50). Female sex (P = .04) and medial location (P = .01) were predictive of an increased risk for reoperation.

Conclusion:

Failure of meniscal repair was not altered with the administration of perioperative ketorolac. Further work studying the effects of longer term anti-inflammatory use after meniscal repair is necessary before stating that this class of medications has no effect on meniscal healing.

Clinical Relevance:

Results of this study suggest that nonsteroidal anti-inflammatory ketorolac can be administered perioperatively during a meniscal repair procedure to harness its benefits of decreased narcotic requirement, decreased pain, and shorter length of hospital stay without negatively influencing the long-term outcome of the surgery.

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.

MR imaging of the postoperative knee

Advances in orthopedic and arthroscopic surgical procedures of the knee such as, knee replacement, ligamentous reconstruction as well as articular cartilage and meniscus repair techniques have resulted in a significant increase in the number of patients undergoing knee arthroscopy or open surgery. As a consequence postoperative MR imaging examinations increase. Comprehensive knowledge of the normal postoperative MR imaging appearances and abnormal findings in the knee associated with failure or complications of common orthopedic and arthroscopic surgical procedures currently undertaken is crucial. This article reviews the various normal and pathological postoperative MR imaging findings following anterior and posterior cruciate ligament, medial collateral ligament and posterolateral corner reconstruction, meniscus and articular cartilage surgery as well as total knee arthroplasty with emphasis on those surgical procedures which general radiologists will likely be faced in their daily clinical routine.

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.

Valid MR imaging predictors of prior knee arthroscopy

PURPOSE

To determine whether fibrosis of the medial patellar reticulum (MPR), lateral patellar reticulum (LPR), deep medial aspect of Hoffa's fat pad (MDH), or deep lateral aspect of Hoffa's fat pad (LDH) is a valid predictor of prior knee arthroscopy.

MATERIALS AND METHODS

Institutional review board approval and waiver of informed consent were obtained for this HIPPA-compliant study. Initially, fibrosis of the MPR, LPR, MDH, or LDH in MR imaging studies of 50 patients with prior knee arthroscopy and 100 patients without was recorded. Subsequently, two additional radiologists, blinded to clinical data, retrospectively and independently recorded the presence of fibrosis of the MPR in 50 patients with prior knee arthroscopy and 50 without. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for detecting the presence of fibrosis in the MPR were calculated. κ statistics were used to analyze inter-observer agreement.

RESULTS

Fibrosis of each of the regions examined during the first portion of the study showed a significant association with prior knee arthroscopy (p < 0.005 for each). A patient with fibrosis of the MPR, LDH, or LPR was 45.5, 9, or 3.7 times more likely, respectively, to have had a prior knee arthroscopy. Logistic regression analysis indicated that fibrosis of the MPR supplanted the diagnostic utility of identifying fibrosis of the LPR, LDH, or MDH, or combinations of these (p ≥ 0.09 for all combinations). In the second portion of the study, fibrosis of the MPR demonstrated a mean sensitivity of 82%, specificity of 72%, PPV of 75%, NPV of 81%, and accuracy of 77% for predicting prior knee arthroscopy.

CONCLUSIONS

Analysis of MR images can be used to determine if a patient has had prior knee arthroscopy by identifying fibrosis of the MPR, LPR, MDH, or LDH. Fibrosis of the MPR was the strongest predictor of prior knee arthroscopy.

Cam impingement of the posterior femoral condyle in medial meniscal tears

PURPOSE

The aim of this study was to compare the results of meniscal repair of the medial meniscus with or without decompression of the posterior segment of the medial meniscus for the treatment of posteromedial tibiofemoral incongruence at full flexion (PMTFI), which induces deformation of the posterior segment on sagittal magnetic resonance imaging (MRI).

METHODS

For more than 2 years, we followed up 27 patients with PMTFI who were classified into the following 2 groups. Group 1 included 8 patients (5 male joints and 3 female joints) with a medial meniscal tear with instability at the site of the tear who underwent meniscal repair. The mean age was 23.6 years. Group 2 included 19 patients (16 male joints and 3 female joints) who had a meniscal tear with instability at the site of the tear and underwent meniscal repair and decompression. The mean age was 26.5 years. In decompression of the posterior segment, redundant bone tissue on the most proximal part of the medial femoral condyle was excised. The patients were assessed by use of the Lysholm score, sagittal MRI at full flexion, and arthroscopic examination.

RESULTS

There were no statistical differences in mean Lysholm score between the 2 groups before surgery, but the mean score in group 2 was significantly higher than that in group 1 after surgery. Meniscal deformation of the posterior segment at full flexion on MRI disappeared in all cases after decompression. On second-look arthroscopy, the rate of complete healing at the site of the tear was 0% in group 1 but 57% in group 2, and it was significantly different between these groups.

CONCLUSIONS

The addition of decompression of the posterior segment of the medial meniscus to meniscal repair of knee joints with PMTFI allowed more room for the medial meniscus to accommodate and improved both function of the knee joint and the rate of success of repair of isolated medial meniscal tears in patients who regularly performed full knee flexion.