Arthroscopic meniscus repair for recurrent subluxation of the lateral meniscus

Anterior Mobility of the Posterior Horn of the Lateral Meniscus Is Associated With Abnormal Magnetic Resonance Imaging Findings of Anteroinferior Popliteomeniscal Fascicle and Posterosuperior Popliteomeniscal Fascicle as Well as a Clinical History of Catching or Locking Symptoms

Purpose

To identify predictors of anterior mobility of the posterior horn of the lateral meniscus (PHLM) among patient demographics (age, sex), clinical characteristics (a history of catching or locking symptoms [CLS], body mass index, alignment of limb), and magnetic resonance imaging (MRI) findings of 4 restraints: anteroinferior popliteomeniscal fascicle (aiPMF), posterosuperior popliteomeniscal fascicle (psPMF), posteroinferior popliteomeniscal fascicle (piPMF), and meniscofibular ligament (MFibL).

Methods

Between October 2010 and December 2014, patients who underwent arthroscopic measurement of mobility of the PHLM were identified. The Sakai classification was used to classify aiPMF and psPMF on MRI into the following 3 types: type A, the fascicle was depicted with obvious continuity and with a low-intensity band; type B, depicted with continuity but with an ambiguous intensity structure; and type C, depicted with discontinuity or not visible. Magnetic resonance images of the piPMF and MFibL were evaluated as presence or absence. The mobility of the PHLM was measured arthroscopically at traction forces of 10 and 20 N.

Results

A total of 73 patients (47 men, mean age 41.8 ± 19.3 years) were included. Multivariate regression analyses revealed aiPMF type C and psPMF types B and C to be independent factors associated with mobility at both traction forces, and CLS was an independent factor at a traction force of 20 N. Compared with that of type A, the increased mobility of aiPMF type C was 5.0 mm (P = .019) and 5.6 mm (P = .011) at 10 and 20 N, respectively; the increased mobility of psPMF type B was 2.5 mm (P = .007) and 3.5 mm (P = .0003), respectively; and the increased mobility of psPMF type C was 3.3 mm (P = .021) and 3.6 mm (P = .014), respectively. The increased mobility associated with CLS was 3.5 mm at 20 N (P = .022).

Conclusions

Anterior displacement of the PHLM induced by an external traction force at 90° of flexion of the knee joint was associated with abnormal MRI findings of the anteroinferior popliteomeniscal fascicle and posterosuperior popliteomeniscal fascicle, as well as a history of catching or locking symptoms.

Clinical Relevance

Understanding signs and symptoms and associated pathology in patients with symptomatic anterior mobility of the posterior horn of the lateral meniscus may help guide best treatment.

Retrospective evaluation of MRI findings in arthroscopically confirmed cases of hypermobile lateral meniscus

OBJECTIVE

To identify preoperative MRI findings in patients with arthroscopically confirmed hypermobile lateral meniscus utilizing a standard MRI knee protocol, with comparison to normal control and lateral meniscal tear groups.

SUBJECTS AND METHODS

All patients with arthroscopically confirmed hypermobile lateral meniscus diagnosed at our institution were retrospectively identified. The following structures were evaluated on preoperative knee MRIs: superior and inferior popliteomeniscal fascicles, lateral meniscus and meniscocapsular junction, popliteal hiatus, and soft tissue edema around the popliteal hiatus. The same MRI features were evaluated in the normal control and lateral meniscal tear groups.

RESULTS

Study, normal control, and lateral meniscal tear patients (18 each) were included. In the study group, 94.4% had superior popliteomeniscal fascicle abnormality, 89.0% had inferior popliteomeniscal fascicle abnormality, and 72.2% had lateral meniscal abnormality. Incidence of these abnormalities was significantly higher than in the normal control group. Meniscal abnormalities in the study group all involved the posterior horn meniscocapsular junction, 12/13 of which had vertical signal abnormality at the junction and 1/13 with anterior subluxation of the entire posterior horn. Popliteus hiatus measurements were largest in the lateral meniscal tear group.

CONCLUSION

In patients with hypermobile lateral meniscus, the combination of popliteomeniscal fascicle abnormality and vertical signal abnormality at the meniscocapsular junction was seen in the majority of patients. Popliteomeniscal fascicle signal abnormality without identifiable lateral meniscal injury was the next most common imaging appearance. Radiologists may provide valuable information by suggesting the diagnosis of hypermobile lateral meniscus in such cases.

Surgical Repair of Hypermobile Lateral Meniscus Secondary to Popliteomeniscal Fascicle Tears Improves Pain and Mechanical Symptoms

Purpose

To describe the clinical and radiographic features associated with isolated hypermobile lateral meniscus (HLM), and report patient outcomes following surgically repaired isolated HLM.

Methods

All patients diagnosed with HLM from 2000 to 2020 at a single academic institution were identified and reviewed. Patients were excluded if they had concomitant ligament injury or lacked 2-year follow-up. Preoperative and postoperative visual analog scale (VAS) pain scores were determined from clinical notes. Statistical analysis was performed in JMP, and statistical significance was determined with use of a paired t-test.

Results

Eighteen knees in 17 patients met inclusion criteria. Mean patient age was 24.1 (range: 6-61) years. Mean follow-up was 73 months (25-151 months). All 18 knees reported pain at presentation; 94% (17/18) had mechanical symptoms. All 18 knees had preoperative MRIs, but only 1 (5.6%) knee was correctly diagnosed by a musculoskeletal trained radiologist. Most repairs were performed with an all-inside technique (61%, 11/18). VAS score improved significantly from 7.2 ± 2.9 preoperatively to 0.7 ± 1.9 postoperatively, with average improvement of VAS score of 6.5 (P < .001). Only one (5.6%) knee required revision meniscal surgery.

Conclusion

Hypermobile lateral meniscus patients commonly see multiple providers, fail to have their HLM diagnosed on MRI, and undergo various treatments prior to a successful diagnosis. Localized lateral joint line pain, mechanical symptoms, and absence of distinct meniscus tear on MRI are the most frequent clinical presentations. Surgery with meniscus repair is a reliable solution to improve pain and mechanical symptoms.

Level of Evidence

Level IV, therapeutic case series.

Discoid lateral meniscus instability in children: part II.: Repair first to minimise the saucerisation

PURPOSE

Despite an improved understanding of discoid lateral meniscus (DLM), the treatment of symptomatic discoid lateral meniscus remains controversial.

METHODS

The aim of this retrospective, single-centred, consecutive-case study was to evaluate the clinical outcome of 60 DLM treated arthroscopically by the "meniscoplasty or saucerisation-suture" technique in children and adolescents [median (range) age 11 (4-17) years], and to investigate surgical failures. The instability was assessed before any saucerisation. The hypotheses were that: (i) the management of instability with suture first was effective and that (ii) a combined classification with clinical and MRI data had a prognostic value.

RESULTS

In 57 knees (95%), the DLM was unstable, and a suture fixation was performed. After a median follow-up of 41.5 months, the median (range) IKDC score was improved from 55 (10-70) preoperatively to 90 (37.5-100) postoperatively. The median (range) Lysholm score at last follow-up was 93.5 (45-100). The procedure was effective in 49 knees (81.6%) after a single procedure. Eleven patients had a failure with a new meniscal tear after a median (range) delay of 42 months (24-60) after the initial procedure. The patterns of discoid lateral meniscus instability were not found to have a prognostic value for surgical failure since they mainly occurred after sport-related injuries. All the patients with initial repair failures but one achieved a good clinical outcome after revision repair without any further meniscectomy.

CONCLUSION

In contrast to adult knees, symptomatic discoid lateral meniscus is rarely stable in children (5%). Meniscal repair is effective to preserve the meniscus tissue, but revision repair became necessary in 18% of the cases and was finally successful. Level of evidence Level III.

Is the popliteal tendon sufficient for all-inside suture in lateral meniscus repair? A 22-case cadaver study

INTRODUCTION

Arthroscopic lateral meniscus repair is performed in the "figure-of-4 position" (supine, with the affected knee flexed and the lower leg crossed over the extended contralateral leg), and anchorage is often on the popliteal tendon. Extending the limb at the end of the procedure alters the relations between the popliteal tendon and the repaired meniscus. The present study aimed to assess lateral meniscal suture fixation on the popliteal tendon after a cycle of flexion-extension.

HYPOTHESIS

Extending the knee can induce suture release.

TYPE OF STUDY

Cadaver study.

MATERIALS AND METHODS

Twenty-two fresh adult human cadaver knee specimens were used. Under arthroscopy with all-inside implants, a vertical suture onto the popliteal tendon was performed through the lateral meniscus. Suture status was assessed under arthroscopy after a cycle of flexion-extension, and deemed defective if the suture was sufficiently loose for the arthroscope to be able to be passed through the popliteal hiatus, if the stitch had passed through the meniscus, or if the suture was broken.

RESULTS

Thirteen sutures (59.1%) remained well fixed, and 9 (40.1%) were defective: 4 (18.2%) were loose, in 4 (18.2%) the stitch had passed through the meniscus, and in 1 (4.5%) the suture had broken.

CONCLUSION

In a population of elderly cadaver knee specimens, arthroscopic suture of the lateral meniscus to the popliteal tendon was defective after flexion-extension in 40% of cases. Stress seems to be exerted on the suture when extension is resumed. Thus, a single stitch seems insufficient for stable lateral meniscus repair.

CLINICAL IMPLICATIONS

Suture of the lateral meniscus to the popliteal tendon undergoes stress when extension is resumed, potentially causing failure of lateral meniscus repair.

LEVEL OF EVIDENCE

IV.

No risk of iatrogenic peroneal nerve injury in all-inside lateral meniscal repair with either 14- or 18-mm needles through the popliteus tendon in the standard arthroscopic knee conditions

PURPOSE

The objectives of this prospective study were to evaluate the risk of peroneal nerve (PN) injury in simulated all-inside lateral meniscal repair with sutures placed through the popliteus tendon (PT) and to determine the optimal needle length.

METHODS

Twenty-nine axial magnetic resonance images (MRI) of postoperative knees with infused intra-articular fluid and in a figure-of-four position were used. The cross-sectional length of the PT was divided into four equal parts with measurements performed at the 25%, 50% and 75% points according to their anteroposterior arrangement. Simulated repairs were performed with 14-mm and 18-mm straight needles via the anteromedial (AM) and anterolateral (AL) portals. Distances from the needle tip following full insertion through the PT to the PN and from the anterior PT border to the posterior knee capsule were measured to determine PN injury risk and ideal needle insertion depths at the different landmarks.

RESULTS

Simulated repairs on the 29 knee MRI images resulted in no incidences of PN injury. The average distances from the needle tip to the PN of the 14-mm needle were significantly greater than the 18-mm needle in all the simulated repairs (P < 0.02), except at the 25% point in the AM approach. When using the 14-mm needle, capsule underpenetration was found in three knees (10.3%) at the 25% point during the AM approach, in one knee (3.4%) at the 50% and 75% points in the AM approach, and in all repairs from the AL portal. The average distances from the anterior PT border to the capsule at the 25%, 50%, and 75% division points on the PT in the AM approach were 7.7 ± 2.7 mm, 7.9 ± 2.5 mm and 7.6 ± 2.8 mm, respectively, whilst in the AL approach were 8.4 ± 2.9 mm, 8.1 ± 2.8 mm and 7.6 ± 2.7 mm.

CONCLUSION

Simulated all-inside lateral meniscal repair with suture placement through the PT with 14-mm and 18-mm needles was safe. The measurements in this study can be used to determine potential PN injury risk in relation to the PT and the appropriate needle length for safe lateral meniscal repairs.

True all inside meniscus repair using the popliteus tendon

The popliteus tendon is a useful anchor point to repair the posterior horn of the lateral meniscus. We describe a new, economical technique that does not violate the neurovascular structures, using an antegrade suture passer and a 2-0 fiberwire to repair the posterior segment including posterior horn of the lateral meniscus taking bites through the capsule and meniscus or the popliteus tendon and meniscus with no anchors in the capsule or popliteus. 9 patients were operated upon using this technique and the mean IKDC score improved from 24.2 to 84, p < 0.01, mean pre op Tegner improved from 1.88 to 6.63 p < 0.01, median hop test from 0 to 4, p = 0 at a mean 15.2 months post surgery. 8 patients had a negative Lachman and 1 grade 2 Lachman at 12 months follow up but was asymptomatic. The Barret's criteria was negative for all 9 patients at latest follow up.

The aspiration test reveals an instability of the posterior horn of the lateral meniscus in almost one-third of ACL-injured patients

PURPOSE

Anterior cruciate ligament (ACL) injuries often lead to associated injuries of the posterior horn of the lateral meniscus (PHLM). Arthroscopic, assessment of PHLM instability may be difficult in the absence of a visible meniscus damage. The main objective of this prospective multi-center study was to compare the ability of the probing and aspiration tests to identify PHLM instability in a population of patients undergoing ACL reconstruction (ACLR) and a control group of patients with an intact ACL undergoing knee arthroscopy.

METHODS

A prospective case-control analysis was performed in three sports medicine centers. One-hundred and three consecutive patients operated for a primary isolated ACLR without structural lateral meniscus damage other than a root tear were included. They were compared to a control group of 29 consecutive patients who had a knee arthroscopy with an intact ACL and no structural lateral meniscus lesion. The probing and aspiration tests were consecutively executed according to previously published methods.

RESULTS

In the control group, no lateral meniscus lesions were visualized during arthroscopy, and both probing and aspiration tests were negative in all patients. In the group of ACL-injured patients, a Forkel type I-III posterolateral meniscus root tear (PLMRT) was found in 12 patients (12%). In this subgroup, the probing test was positive in 4/12 patients (33%) and the aspiration test in 5 additional patients (75%). In 15 patients (15%), an elongation of the posterior root of the lateral meniscus (defined as type IV PLMRT as an addendum to the Forkel classification) could be observed during arthroscopy. In this subgroup, only 1 patient displayed a PHLM instability with the probing test (7%), whereas the aspiration test was positive in 13/15 patients (87%). In the remaining 76 patients (74%), no structural lesion of the PHLM could be identified. Nevertheless, an instability of the PHLM could be identified in 8 of them (11%) with the probing test, and the aspiration test was positive in 2 additional knees (13%) of this apparently normal subgroup. Altogether, in the entire ACL injury cohort, a positive probing test was observed in 13/103 patients (13%) and a positive aspiration test in 32/103 knees (31%) (p < 0.01).

CONCLUSION

Careful observation and examination of the PHLM with the aspiration test revealed a substantial amount of previously undiagnosed lateral meniscus instabilities in ACL-injured knees. The prevalence of PHLM instability as evaluated by the aspiration test was high (31%). The aspiration test was superior to the probing test in detecting an instability of the PHLM in a population of ACL-injured patients.

LEVEL OF EVIDENCE

II.

Preoperative Magnetic Resonance Imaging as a Diagnostic Aid for Hypermobile Lateral Meniscus

Background: Hypermobile lateral meniscus is difficult to diagnose with imaging due to its absence of tears or anomalies. We aimed to clarify the accuracy of the preoperative diagnosis using magnetic resonance imaging (MRI). Methods: The preoperative MRI status of the posterosuperior popliteomeniscal fascicle (sPMF), anteroinferior popliteomeniscal fascicle (iPMF), and popliteal hiatus were examined retrospectively on sagittal images in the hypermobile lateral meniscus group (n = 22) and an age- and gender-matched control group (n = 44). These statuses were evaluated by a logistic regression analysis to assess their degree of diagnostic accuracy. Results: The area under the curve (AUC) of the sPMF, iPMF, popliteal hiatus, and all three criteria combined was 0.66, 0.74, 0.64, and 0.77, respectively (low, moderate, low, and moderate accuracy, respectively). The odds ratios of the most severe type 3 forms of the sPMF, iPMF, and popliteal hiatus for hypermobile lateral meniscus were significantly high (5.50, 12.20, and 5.00, respectively). Although the diagnostic accuracy was not high enough, the significantly higher odds ratio for type 3 may indicate a hypermobile lateral meniscus. Conclusion: a definitive diagnosis of hypermobile lateral meniscus is difficult with MRI findings alone; however, MRI evaluations of the iPMF, sPMF, and the widening of popliteal hiatus can be used as an adjunct to diagnosis.

Tears of the Popliteomeniscal Fascicles of the Lateral Meniscus: An Arthroscopic Classification

OBJECTIVE

To bring forward an arthroscopic classification of the popliteomeniscal fascicles of the lateral meniscus (PFLM) tears.

DESIGN

Six fresh frozen knee joint samples of adult males were chosen, and the lateral meniscus at the popliteal hiatus region were measured to analyze their anatomic relationship. Patients who had received magnetic resonance imaging scan at knee joint before the surgery and diagnosed as PFLM tears by arthroscopy from April 2014 to October 2017 were selected. Data regarding the integrity of PFLM were prospectively recorded in a data registry. Tear morphology and treatment received were subsequently extracted by 2 independent reviewers from operative notes and arthroscopic surgical photos.

RESULTS

The average length and thickness of the popliteal hiatus of the lateral meniscus were 2.09 ± 0.21 cm and 0.43 ± 0.08 cm, respectively. The average length of anterosuperior popliteomeniscal fascicle (APF) was 0.87 ± 0.18 cm, and the posterosuperior popliteomeniscal fascicle (PPF) was 0.72 ± 0.15 cm. A total of 36 PFLM tears in 36 patients were divided as type I (APF tear; n = 5, 13.9%), type II (PPF tear; n = 20, 55.6%), and type III (both APF and PPF tears; n = 11, 30.6%). All patients were treated with arthroscopic all-inside repair using a suture hook for the PFLM tears and follow-up for 21.1 months. All patients have done well with significantly improved Lysholm and International Knee Documentation Committee scores at the last follow-up relative to preoperative scores (P < 0.01).

CONCLUSION

This study suggests to possibly classify the PFLM tears for clinical practice.

Repair of popliteomeniscal fascicles tear using a posterior transseptal portal fixes hypermobile lateral meniscus

PURPOSE

This study investigates the effects of the all-inside repair of posterosuperior popliteomeniscal fascicle (PMF) on lateral meniscus stabilization using a posterior arthroscopic approach.

METHODS

Between 2015 and 2018, 17 patients with hypermobile lateral meniscus (HLM) underwent posterior knee arthroscopy for PMF repair. The all-inside repair was performed through posteromedial transseptal and posterolateral portals using a suture hook technique. Patients were clinically assessed based on IKDC and Lysholm scores.

RESULTS

Both IKDC and Lysholm scores improved significantly after an average follow-up of 3.5 years (P < 0.001). No patients underwent reoperation, and no complications associated with posterior knee arthroscopy were reported.

CONCLUSION

The all-inside suture hook technique using posterolateral and posteromedial transseptal portals fixes HLM with excellent IKDC and Lysholm scores.

LEVEL OF EVIDENCE

Level IV.

[Arthroscopic classification and management for the popliteal hiatus of the lateral meniscus tears]

OBJECTIVE

To bring forward an arthroscopic classification of the popliteal hiatus of the lateral meniscus (PHLM) tears and to assess the effects of arthroscopic all-inside repair with suture hook in management of such injuries.

METHODS

This study involved 146 patients who underwent arthroscopic operation because of PHLM tears from April 2014 to October 2017, eliminating the patients who had discoid lateral meniscus. There were 81 males and 65 females, with 54 left knees and 92 right knees. The average ages were (34.7±3.7) years. Among the selected participants, there were 107 patients with anterior cruciate ligament (ACL) injuries, 39 patients with medial collateral ligament (MCL) injuries, and 48 patients with medial meniscus tears. The average preoperative Lysholm and International Knee Documentation Committee (IKDC) scores were 57.7±9.2 and 54.1±8.9, respectively. The arthroscopic classification was based on the extent and degree of PHLM tears and using the arthroscopic all-inside repair with suture hook for such injuries. For the patients associated with ACL injuries, the ipsilateral autograft hamstring tendons use as the reconstruction graft for single bundle ACL reconstructions. The suture anchors were used for treatment of MCL Ⅲ injuries, and the arthroscopic all-inside repair for medial meniscus tears.

RESULTS

A total of 146 PHLM tears in 146 patients were divided into type Ⅰ (tears not involved in popliteus tendon incisura; n=86, 58.9%), type Ⅱ (tears involved in popliteomeniscal fascicles; n=36, 24.7%), and type Ⅲ (tears involved in popliteus tendon incisura; n=24, 16.4%). For type Ⅰ, there were three subtypes, including type Ⅰa: longitudinal tear (n=53, 61.6%), type Ⅰb: horizontal tear (n=27, 31.4%), and type Ⅰc: radial tear (n=6, 7.0%). For type Ⅱ, there were also three subtypes, including type Ⅱa: anterosuperior popliteomeniscal fascicle tear (n=5, 13.9%), type Ⅱb: posterosuperior popliteomeniscal fascicle tear (n=20, 55.6%), and type Ⅱc: both tears (n=11, 30.6%). For type Ⅲ, there were two subtypes, including type Ⅲa: horizontal tear (n=9, 37.5%), type Ⅲb: radial tear (n=15, 62.5%). In the follow-up for an average of 15.3±2.6 months, all the patients had done well with significantly improved Lysholm (84.6±14.3) and IKDC (83.2±12.8) scores at the end of the last follow-up relative to preoperative scores (P > 0.01).

CONCLUSION

We propose that it is possible to classify lateral meniscus tears at the popliteal hiatus region for three types, which can summarize the injury characteristics of this area. The arthroscopic all-inside repair with suture hook for the PHLM tears can avoid stitching to popliteal tendon or narrowing popliteal hiatus and have satisfactory clinical results.

Examination of refractory discoid lateral meniscus injury

BACKGROUND

Lateral discoid meniscus (LDM) should be treated and preserved with saucerization and/or suture repair. However, repair of the meniscal hoop structure is sometimes difficult due to displacement or large defects. In this study, we aimed to examine tear patterns based on the Ahn classification in those requiring meniscal repair and those undergoing subtotal meniscectomy.

METHODS

Twenty-three patients were evaluated (mean age, 27.4 years; mean follow-up period, 2.5 years). The following were evaluated: displacement morphology based on the Ahn classification, site of tear under arthroscopy, morphology, surgical procedure, Lysholm score at final postoperative follow-up, and clinical outcome of meniscus using Barrett's criteria.

RESULT

There were 16 knees without displacement (saucerization with suture repair, 13 knees; subtotal meniscectomy, 3 knees) and 10 knees with displacement (reduction with suture repair, 3 knees; subtotal meniscectomy, 7 knees). Subtotal meniscectomy was performed more often in cases with dislocation, especially in the central shift type as defined by the Ahn classification. The mean Lysholm score was 65.0 points preoperatively and 95.3 points postoperatively. Twenty-three knees (88%) were postoperatively categorized under the Barrett's criteria as healing and 3 knees (12%) were categorized as non-healing. The number of non-healing cases that underwent subtotal meniscectomy was relatively small (1 of 10 knees), and the short-term results were not poor.

CONCLUSION

Localized peripheral longitudinal tears tended to be repairable even with displacement, while peripheral tears covering the entire meniscus or with severe defects/tears in the body of the meniscus tended to be difficult to repair, leading to subtotal meniscectomy.

Widening of the popliteal hiatus on sagittal MRI view plays a critical role in the mechanical signs of discoid lateral meniscus

PURPOSE

This study was undertaken to elucidate the clinical significance of widening of the popliteal hiatus on magnetic resonance imaging (MRI) after a torn discoid lateral meniscus (DLM).

METHODS

Included are 125 knees with meniscal disorders after arthroscopic surgery, divided according to preoperative MRI and symptoms into group A (torn DLM with mechanical symptoms,11 knees); group B (torn DLM without mechanical symptoms,41 knees); group C (asymptomatic DLM, 19 knees); and group D (medial meniscal tears, 54 knees). Popliteal hiatus width was measured on sagittal and coronal MRI. During arthroscopy, total meniscectomy or central partial meniscectomy combined repair of the remaining part was performed in group A and group B. Outcomes were evaluated with MRI, the Tegner, Lysholm Knee Scoring Scale, and visual analog scale (VAS) scores.

RESULTS

The preoperative width of the popliteal hiatus was significantly larger in group A than in groups C and D (P < 0.05) on both views. Group A had a wider popliteal hiatus on sagittal view compared with group B (P < 0.05); group B had a wider popliteal hiatus on coronal view compared with group D (P < 0.05). The width of the popliteal hiatus on sagittal view was significantly reduced after surgery in group A (P < 0.05). In groups A and B, Lysholm and Tegner scores were improved, while VAS scores were reduced (all P < 0.05).

CONCLUSION

Widening of the popliteal hiatus on MRI was correlated with torn DLM and accompanied mechanical symptoms. Arthroscopic central partial menisectomy and stabilization of the posterior part of the middle body anterior to the popliteus tendon were effective for the treatment of torn DLM. These findings may help guide appropriate treatment for torn DLM.

LEVEL OF EVIDENCE

II.

Posterolateral approach for all-inside arthroscopic lateral meniscus repair in athletes: technique and outcomes

INTRODUCTION

The past 2 decades have been marked by substantial progress in our knowledge of meniscus anatomy, function, and biomechanics, and also by the shifting of the surgical treatment of meniscal lesions from traditional meniscectomy towards arthroscopic repair to get away from the early osteoarthritis associated with meniscectomy. Posterior horn injuries of the lateral meniscus (LM) have been less studied due to their lower incidence and also due to the historical technical complexity of performing a repair in the posterolateral compartment.

MATERIALS AND METHODS

A retrospective analysis of prospectively collected data was performed of all athletic patients who had a peripheral longitudinal tear of the lateral meniscal posterior horn and who underwent at least one repair procedure with a posterolateral approach between 2014 and 2018. The type of injury, extent of lateral meniscal tear, and characteristics of sutures placed were assessed. Clinical assessment included objective and subjective IKDC ratings. The Tegner activity level score was determined before the injury and at the last follow-up visit. Failure was defined as a need for revision surgery. All complications were documented.

RESULTS

The study population comprised 24 athletes with a mean follow-up of 25.2 ± 10 months. The Tegner activity level was exactly the same before the injury as after the surgery. The mean IKDC score significantly increased from 41.8 (12.2) before the surgery to 94.5 (9.1) after. There were four reoperations for failure (16.6%) that required a new suture repair. None of these revised repairs sustained a new failure as of the last follow-up.

CONCLUSION

Despite the long learning curve, the posterolateral approach is a safe and effective technique for longitudinal tears of the posterior horn of the LM. The results of all-inside suture repair through a posterolateral portal are comparable to other techniques.

Can an injured discoid lateral meniscus be returned to the correct anatomic position and size of the native lateral meniscus after surgery?

BACKGROUND

No previous studies have compared the position and size of the remaining discoid lateral meniscus (DLM) with that of a normal lateral meniscus. This study aimed to evaluate the postoperative position and size of DLM compared with that of normal controls using magnetic resonance imaging (MRI).

METHODS

This retrospective study involved 52 symptomatic complete type DLMs (discoid group) who underwent arthroscopic surgery and 50 normal controls (control group). Pre- and postoperative MRI evaluations, height, width, and relative percentage of extrusion (RPE) were assessed. Sagittal position parameters, including distances from articular cartilage center to anterior meniscus (CAMD) and from anterior articular cartilage margin to anterior horn (ACMD), were also assessed. Logistic regression analysis was performed to find factors with extrusion of remaining DLM.

RESULTS

The height of the discoid group was significantly lower than that of the control group (P = 0.000). RPE in the discoid group was significantly larger than in the control group (P = 0.005). Only CAMD and ACMD in the discoid group were different (positioned more anteriorly) from the control group (P = 0.000). Preoperative meniscal shift (odds ratio (OR): 12.448; P = 0.003) and operative technique, especially partial meniscectomy with repair (OR: 19.125; P = 0.000), were the major factors associated with extrusion.

CONCLUSION

The width of remaining DLM was comparable to that of normal controls, but the position was found to be more anterior and lateral than that of normal controls. Preoperative meniscal shift and combined meniscus repair were the major factors for smaller width and greater extrusion; thus, surgeons should address and counsel these factors before surgery.

Widening of the popliteal hiatus on magnetic resonance imaging leads to recurrent subluxation of the lateral meniscus

PURPOSE

This study was undertaken to elucidate the clinical significance of widening of the popliteal hiatus on magnetic resonance imaging (MRI), and to document the clinical results and technical aspects of arthroscopic repair of this finding.

METHODS

Included are 82 knees after arthroscopic surgery, divided according to arthroscopic diagnosis into group A, hypermobility of lateral meniscus, 8 knees; group B, tear of the anterior horn of the lateral meniscus, 32 knees; and group C, no abnormality of the lateral meniscus, 36 knees with medial meniscal tears and 6 with other conditions. Popliteal hiatus diameter was measured and the popliteal hiatus/lateral tibial plateau (LTP) ratio was calculated on preoperative sagittal and coronal MRI. At arthroscopy, the widened popliteal hiatus in group A was tightened anteriorly by outside-in or all-inside suture and posteriorly with all-inside suture. Outcomes were evaluated with MRI, Lysholm, Tegner and VAS scores.

RESULTS

The preoperative diameter of the popliteal hiatus and the popliteal hiatus/LTP ratio were significantly larger in group A than in groups B and C (p < 0.05) on both views. Threshold popliteal hiatus/LTP values of 0.16 and 0.18 on the sagittal and coronal views demonstrated diagnostic discrimination, and these values were significantly reduced after arthroscopy in Group A. Lysholm and Tegner scores were improved after tightening of the popliteal hiatus, while VAS scores reduced (all p < 0.05).

CONCLUSION

Widening of the popliteal hiatus on MRI may lead to recurrent subluxation of the lateral meniscus. Arthroscopic anterior and posterior tightening of the popliteal hiatus was a safe and effective treatment.

LEVEL OF EVIDENCE

II.

Quantitative and Qualitative Assessment of Posterolateral Meniscal Anatomy: Defining the Popliteal Hiatus, Popliteomeniscal Fascicles, and the Lateral Meniscotibial Ligament

BACKGROUND

Surgical treatment of lateral meniscal tears can be challenging due to the greater mobility of the lateral meniscus, thin capsule, and management of the popliteal hiatus. There has been a lack of quantitative assessments of the structural attachments to the posterior horn of the lateral meniscus (PHLM) to guide repairs.

PURPOSE

To qualitatively and quantitatively describe the anatomy of the PHLM, popliteomeniscal fascicles, and the posterolateral capsule.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Fourteen male, nonpaired, fresh-frozen cadaveric knees were used. The attachments of the posterolateral capsule, popliteomeniscal fascicles, and meniscofemoral ligaments to the lateral meniscus and the attachment of the meniscotibial ligament to the tibia were identified. A 3-dimensional coordinate measuring system was used to measure the relationships of these attachments to surgically relevant landmarks and their structural relationship with the lateral meniscus.

RESULTS

The posterolateral capsule attachment had a confluent attachment at the superior margin of the PHLM, quantitatively attaching to the proximal 11% of the total height of the PHLM. On average, the length of the posterolateral capsule attachment to the superior surface of the PHLM was 16.7 ± 2.7 mm. The average length of the meniscotibial attachment to the posteroinferior aspect of the meniscus was 12.8 ± 3.9 mm. There was a lack of ligamentous attachments to the lateral meniscus between the lateral aspect of the meniscotibial ligament and the anterior aspect of the anterosuperior popliteomeniscal fascicle, where only popliteomeniscal fascicle and capsular attachments to the posterior meniscus were present.

CONCLUSION

This anatomic study provides quantitative guidelines for the complex attachments to the PHLM. Knowledge of the quantitative descriptions of these attachments may aid in an improved intraoperative diagnosis of PHLM tears that extend to the popliteal hiatus, and further studies related to the surgical repair of the intricate attachments to the PHLM are recommended.

CLINICAL RELEVANCE

The findings of this study provide the anatomic foundation for an improved understanding of the role of the meniscocapsular, meniscotibial, and popliteomeniscal fascicle attachments of the posterolateral meniscus. Understanding the differences between the lengths of the superior and inferior aspects of the popliteal hiatus will help to further refine characterization of tears extending into the popliteal hiatus and to avoid potential overconstraint of the more mobile lateral meniscus during a repair by anatomically reproducing its native structural attachments.

Defining a Safe Zone for All-Inside Lateral Meniscal Repairs in Pediatric Patients: A Magnetic Resonance Imaging Study

PURPOSE

To establish a safe zone for all-inside meniscal fixation in pediatric patients by use of magnetic resonance imaging (MRI) measurements between the popliteal tendon (PT) and popliteal neurovascular bundle (PNVB).

METHODS

Patients aged 5 to 16 years with normal or nearly normal knee MRI scans were included. They were grouped by age: group I, 5 to 7 years (n = 61); group II, 8 to 10 years (n = 59); group III, 11 to 13 years (n = 60); and group IV, 14 to 16 years (n = 70). At the level of the lateral meniscus, 2 lines starting at the lateral patellar tendon border and ending at the medial edge of the PT (D1) and the lateral edge of the PNVB (D2) were made on an axial knee MRI scan. A third line (D3) connected D1 to D2 at the meniscocapsular junction of the posterior horn of the lateral meniscus (PHLM). A fourth line (D4), derived geometrically, was parallel and 8 mm anterior to D3, simulating the anterior edge of the PHLM.

RESULTS

Axial MRI scans of 250 pediatric patients (aged 5-16 years) were retrospectively reviewed. Analysis showed significant correlation between age and sex for D3 (P < .0001). For D3, there were significant differences among all age groups, except between groups III and IV. The average D3 by age group was 14.1 mm (standard deviation [SD], 3.1 mm) for group I, 15.8 mm (SD, 2.5 mm) for group II, 17.0 mm (SD, 3.3 mm) for group III, and 17.2 mm (SD, 3.1 mm) for group IV. The average D4 was 11.39 mm (SD, 2.6 mm), 13.24 mm (SD, 2.24 mm), 14.59 mm (SD, 2.89 mm), and 14.80 mm (SD, 2.79 mm), respectively. There were significant differences in D3 and D4 in male versus female patients (17.6 mm vs 15.7 mm, P < .001, and 14.9 mm vs 13.2 mm, P < .001, respectively), particularly in groups III and IV (17.0 mm vs 13.8 mm and 16.8 mm vs 13.9 mm, respectively).

CONCLUSIONS

This study provides normative data of the distance between the PNVB and PT at the meniscocapsular junction (D3) and anterior edge of the PHLM (D4) with the knee in full extension. Combined with previous studies showing that the addition of knee flexion increases the distance between the meniscus and the neurovascular bundle, these data can be used by surgeons to improve the safety of PHLM repair in pediatric patients.

LEVEL OF EVIDENCE

Level III, diagnostic study of nonconsecutive patients.

The popliteus tendon provides a safe and reliable location for all-inside meniscal repair device placement

PURPOSE

Repairs of the posterior horn of the lateral meniscus can be technically challenging. In contrast to medial meniscus repairs, the capsule around the posterior segment attachment of the lateral meniscus is quite thin. This study evaluates the clinical results of an arthroscopic all-inside repair technique for unstable, vertical, lateral meniscus tears, using a suture repair placed directly into the popliteus tendon.

METHODS

A retrospective analysis of prospectively collected data from the SANTI database was performed. All patients who had undergone combined ACL reconstruction with lateral meniscus all-inside repair, using sutures placed in the popliteus tendon, between 2011 and 2015, were included. Patients were reviewed clinically at 1 and 2 years' follow-up. At final follow-up, all patients were contacted to identify if they underwent further surgery or had knee pain, locking or effusion. Symptomatic patients were recalled for clinical evaluation by a physician and Magnetic Resonance Imaging of the knee. Operative notes for those undergoing further surgery were reviewed and rates and type of re-operation, including for failed lateral meniscal repair were recorded.

RESULTS

Two hundred patients (mean age 28.6 ± 10.2 years) with a mean follow-up of 45.5 ± 12.8 months (range 24.7-75.2) were included. The mean Subjective International Knee Documentation Committee (IKDC) at final follow-up was 85.0 ± 11.3. The post-operative mean side-to-side laxity measured at 1 year was 0.6 ± 1.0 mm. Twenty-six patients underwent re-operation (13%) at a mean follow-up of 14.8 ± 7.8 months. The ACL graft rupture rate was 5.0%. Other causes for re-operation included medial meniscus tear (2.5%), cyclops lesion (1.5%) and septic arthritis (0.5%). The lateral meniscus repair failure rate was 3.5%. No specific complications relating to placement of sutures in the popliteus tendon were identified.

CONCLUSION

Arthroscopic all-inside repair of unstable, vertical, lateral meniscus tears using a suture placed in the popliteus tendon is a safe technique. It is associated with a very low failure rate with no specific complications.

LEVEL OF EVIDENCE

Level IV.

Midterm outcomes after arthroscopic surgery for hypermobile lateral meniscus in adults: Restriction of paradoxical motion

BACKGROUND

Hypermobile lateral meniscus (HLM) is one of the causes of knee pain and a locking sensation. It is thought that disruption of the popliteomeniscle fascicles lead to hypermobility of the lateral meniscus in adults. In cases of HLM, the posterior portion of the lateral meniscus shows forward abnormal translation with knee flexion and backward translation with knee extension. We refer to this phenomenon as paradoxical motion. The purpose of this study was to report an arthroscopic HLM stabilization and evaluate the midterm clinical outcomes.

METHODS

Twenty consecutive HLM patients (21 knees) who underwent arthroscopic surgery were included. The mean age at the time of surgery was 37.7 (19-63) years. Mean duration from surgery to final follow-up was 37 (24-68) months. Meniscus movement according to the knee flexion and extension was observed by diagnostic arthroscopy. We performed arthroscopic inside-out vertical stacked suturing of disrupted popliteomeniscle fascicles. The number of suturing and details of meniscal movement were assessed. The Tegner activity level score and Lysholm knee scores were determined preoperatively and at 2 years postoperatively. Clinical outcomes included locking sensation, recurrences and complications reported at the final follow-up.

RESULTS

Paradoxical motion of the lateral meniscus was observed in all patients. We performed an average of 5.0 (2-8) vertical stacked sutures of the disrupted popliteomeniscal fascicles. Physiological motion of the lateral meniscus was observed after meniscus repairs. The mean Tegner activity level scales before and after surgery were 4.6 (2-8) and 4.7 (2-8), respectively. The mean Lysholm knee scores significantly improved from 72.0 (48-85) preoperatively to 97.8 (78-100) at 2 years postoperatively. There were no complications or recurrences of locking symptoms at the final follow-up.

CONCLUSIONS

Use of arthroscopic inside-out vertical sutures for disrupted popliteomeniscle fascicles improved the clinical outcomes for HLM patients without complications.