Isolated Posterior Lateral Meniscofemoral Ligament Tears Show Greater Meniscal Extrusion in Knee Extension, and Isolated Posterior Lateral Meniscal Root Tears Show Greater Meniscal Extrusion at 30° Using Ultrasound: A Cadaveric Study.

PURPOSE: To quantify the effects that posterior meniscofemoral ligament (pMFL) lesions have on lateral meniscal extrusion (ME) both with and without concomitant posterior lateral meniscal root (PLMR) tears and describe how lateral ME varied along the length of the lateral meniscus. METHODS: Ultrasonography was used to measure ME of human cadaveric knees (n = 10) under the following conditions: control, isolated pMFL sectioning, isolated PLMR sectioning, pMFL+PLMR sectioning, and PLMR repair. ME was measured anterior to the fibular collateral ligament (FCL), at the FCL, and posterior to the FCL in both unloaded and axially loaded states at 0° and 30° of flexion. RESULTS: Isolated and combined pMFL and PLMR sectioning consistently demonstrated significantly greater ME when measured posterior to the FCL compared with other image locations. Isolated pMFL tears demonstrated greater ME at 0° compared with 30° of flexion (P < .05), whereas isolated PLMR tears demonstrated greater ME at 30° compared with 0° of flexion (P < .001). All specimens with isolated PLMR deficiencies demonstrated greater than 2 mm of ME at 30° flexion, whereas only 20% of specimens did so at 0°. When the pMFL was sectioned following an isolated PLMR tear, there was a significant increase in ME at 0° (P < .001). PLMR repair after combined sectioning restored ME to levels similar to that of controls in all specimens when measured at and posterior to the FCL (P < .001). CONCLUSIONS: The pMFL protects against ME primarily in full extension, whereas the presence of ME in the setting of PLMR injuries may be better appreciated in knee flexion. With combined tears, isolated repair of the PLMR can restore near-native meniscus position. CLINICAL RELEVANCE: The stabilizing properties of intact pMFL may mask the presentation of PLMR tears and delay appropriate management. Additionally, the MFL is not routinely assessed during arthroscopy due to difficult visualization and access. Understanding the ME pattern of these pathologies in isolation and combination may improve detection rates so that the source of patients' symptoms can be addressed to satisfaction.

Medial Meniscal Extrusion of Greater Than 3 Millimeters on Ultrasound Suggests Combined Medial Meniscotibial Ligament and Posterior Medial Meniscal Root Tears: A Cadaveric Analysis.

PURPOSE: To evaluate how the meniscotibial ligament (MTL) affects meniscal extrusion (ME) with or without concomitant posterior medial meniscal root (PMMR) tears and to describe how ME varied along the length of meniscus. METHODS: ME was measured using ultrasonography in 10 human cadaveric knees in conditions: (1) control, either (2a) isolated MTL sectioning, or (2b) isolated PMMR tear, (3) combined PMMR+MTL sectioning, and (4) PMMR repair. Measurements were obtained 1 cm anterior to the MCL (anterior), over the MCL (middle), and 1 cm posterior to the MCL (posterior) with or without 1,000 N axial loads in 0° and 30° flexion. RESULTS: At 0°, MTL sectioning demonstrated greater middle than anterior (P < .001) and posterior (P < .001) ME, whereas PMMR (P = .0042) and PMMR+MTL (P < .001) sectioning demonstrated greater posterior than anterior ME. At 30°, PMMR (P < .001) and PMMR+MTL (P < .001) sectioning demonstrated greater posterior than anterior ME, and PMMR (P = .0012) and PMMR+MTL (P = .0058) sectioning demonstrated greater posterior than anterior ME. PMMR+MTL sectioning demonstrated greater posterior ME at 30° compared with 0° (P = .0320). MTL sectioning always resulted in greater middle ME (P < .001), in contrast with no middle ME changes following PMMR sectioning. At 0°, PMMR sectioning resulted in greater posterior ME (P < .001), but at 30°, both PMMR and MTL sectioning resulted in greater posterior ME (P < .001). Total ME surpassed 3 mm only when both the MTL and PMMR were sectioned. CONCLUSIONS: The MTL and PMMR contribute most to ME when measured posterior to the MCL at 30° of flexion. ME greater than 3 mm is suggestive of combined PMMR + MTL lesions. CLINICAL RELEVANCE: Overlooked MTL pathology may contribute to persistent ME following PMMR repair. We found isolated MTL tears able to cause 2 to 2.99 mm of ME, but the clinical significance of these magnitudes of extrusion is unclear. The use of ME measurement guidelines with ultrasound may allow for practical MTL and PMMR pathology screening and pre-operative planning.

Prospective Randomized Trial of Biologic Augmentation With Bone Marrow Aspirate Concentrate in Patients Undergoing Arthroscopic Rotator Cuff Repair.

BACKGROUND: Although initial studies have demonstrated that concentrated bone marrow aspirate (cBMA) injections promote rotator cuff repair (RCR) healing, there are no randomized prospective studies investigating clinical efficacy. HYPOTHESIS/PURPOSE: To compare outcomes after arthroscopic RCR (aRCR) with and without cBMA augmentation. It was hypothesized that cBMA augmentation would result in statistically significant improvements in clinical outcomes and rotator cuff structural integrity. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Patients indicated for aRCR of isolated 1- to 3-cm supraspinatus tendon tears were randomized to receive adjunctive cBMA injection or sham incision. Bone marrow was aspirated from the iliac crest, concentrated using a commercially available system, and injected at the aRCR site after repair. Patients were assessed preoperatively and serially until 2 years postoperatively via the following functional indices: American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), Simple Shoulder Test, 12-Item Short Form Health Survey, and Veterans RAND 12-Item Health Survey. Magnetic resonance imaging (MRI) was performed at 1 year to assess rotator cuff structural integrity according to Sugaya classification. Treatment failure was defined as decreased 1- or 2-year ASES or SANE scores as compared with preoperative baseline, the need for revision RCR, or conversion to total shoulder arthroplasty. RESULTS: An overall 91 patients were enrolled (control, n = 45; cBMA, n = 46): 82 (90%) completed 2-year clinical follow-up and 75 (82%) completed 1-year MRI. Functional indices significantly improved in both groups by 6 months and were sustained at 1 and 2 years (all P < .05). The control group showed significantly greater evidence of rotator cuff retear according to Sugaya classification on 1-year MRI (57% vs 18%; P < .001). Treatment failed for 7 patients in each group (control, 16%; cBMA, 15%). CONCLUSION: cBMA-augmented aRCR of isolated supraspinatus tendon tears may result in a structurally superior repair but largely fails to significantly improve treatment failure rates and patient-reported clinical outcomes when compared with aRCR alone. Additional study is warranted to investigate the long-term benefits of improved repair quality on clinical outcomes and repair failure rates. REGISTRATION: NCT02484950 (ClinicalTrials.gov identifier).

Neoadjuvant radiation influences the pseudocapsule in soft tissue sarcoma: A histopathologic and radiographic evaluation.

BACKGROUND AND OBJECTIVES: A pseudocapsule surrounds soft tissue sarcoma (STS). Its composition, response to neoadjuvant radiation, and clinical significance are poorly understood. METHODS: Seventeen cases of high-grade undifferentiated pleomorphic sarcoma (UPS) were reviewed, ten of which were treated with neoadjuvant radiation. Magnetic resonance imaging (MRI) studies, pathology slides, and patient records were reviewed. RESULTS: Irradiated pseudocapsules were well-demarcated with fewer viable tumor cells and were thicker on both pathology and MRI measurements when compared to non-irradiated pseudocapsules (p < 0.001, p = 0.04, respectively). Pseudocapsule mean pathology width (MPW) was positively correlated with tumor necrosis percentage (p = 0.044), and negatively correlated with mitotic rate (p = 0.043), though pseudocapsule width measured on MRI did not correlate with these prognostic factors. Despite an evident treatment response to neoadjuvant radiation, viable tumor cells were present within the pseudocapsule and the surrounding healthy tissue. CONCLUSIONS: The pseudocapsule in STS responds to radiation and there appears to be a correlation between pseudocapsule width and tumor necrosis and mitotic activity. As viable tumor cells are present beyond the pseudocapsule, surgeons should remain cautious in determining margins of resection in STS when using the pseudocapsule as a palpable landmark. This novel study is the most detailed to date to describe the histopathologic and radiographic characteristics of the STS pseudocapsule. Further studies are needed to determine the clinical significance of the pseudocapsule.