Faculty Bibliography

The subchondral bone is a critical part of the osteochondral unit, providing nutrients to the overlying articular cartilage, thereby maintaining viability of the chondral tissue. The subchondral bone also provides firm mechanical support to assist with stability of the articular cartilage and distribution of stress. Subchondral bone pathology, diagnosed as a bone marrow lesion (BML) on magnetic resonance imaging, may be seen in a variety of pathologic conditions, including knee osteoarthritis (OA). Bone marrow lesions accelerate degenerative changes in the knee joint, and treatment of these lesions may prolong joint longevity. Presently, treatment options for subchondral bone lesions are limited. Osteo-core plasty is a minimally invasive treatment for subchondral bone pathology that consists of two parts: (1) decompression of bone marrow and the administration of bone marrow aspirate concentrate (BMAC) to promote tissue healing, and (2) implantation of bone autograft to provide mechanical support. In an observational study 24 patients with bone marrow lesions have been treated with Osteo-core plasty due to symptomatic bone marrow lesions. At 2 year follow-up they showed a significant improvement in patient-reported scores compared to the preoperative assessment. Based on early clinical data Osteo-core plasty has demonstrated clinical efficacy in treatment of symptomatic bone marrow lesions associated with knee osteoarthritis.

Massive and retracted tears of the supraspinatus and infraspinatus tendons of the rotator cuff are associated with great pain and disability and may be considered "non-repairable," depending on the extent of injury and the experience of the treating clinician. The technique of anatomic vector repair of the rotator cuff is a surgical treatment method that enables the surgeon to accurately characterize the injury pattern and successfully repair many of these debilitating injuries anatomically in a stepwise manner, often in cases that would have otherwise been treated with a less preferable surgical procedure that does not restore native anatomy.

BACKGROUND:Surgical treatment of osteochondral lesions of the talus affecting the medial aspect of the talar dome is typically performed using medial malleolar osteotomy to optimize access. This study compares clinical outcomes of lesions repaired using biologic inlay osteochondral reconstruction in patients who did or did not undergo medial malleolar osteotomy, depending on defect dimensions. METHODS:Patients treated for osteochonral lesions of the talus through a medial mallolar approach or arthroscopically-assisted approach were prospectively followed. Assessment tools consisted of the visual analogue scale (VAS) and the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot score (AOFAS). The magnetic resonance observation of cartilage repair tissue (MOCART) score was used postoperatively. RESULTS:Data for 24 patients (mean age 34years, mean follow-up 22 months) was analyzed. Mean preoperative/final AOFAS and VAS in those who underwent osteotomy were 57.7/81.2 and 5.7/1.9 (p<0.001), respectively. In those who underwent arthroscopically-assisted reconstruction, mean preoperative/final AOFAS and VAS were 54.4/84.0 and 7.6/2.0 (p<0.001), respectively. There was no difference in mean MOCART score (p=0.662) for those treated with osteotomy (67.3) compared to those without (70.8). CONCLUSIONS:Osteochondral lesions of the talar dome can be treated successfully by biological inlay osteochondral reconstruction technique without medial malleolar osteotomy, with good to excellent clinical outcomes expected. MRI demonstrates good integration of the graft into surrounding tissue.

BACKGROUND:/UNASSIGNED:Surgical treatment to repair partial anterior cruciate ligament (ACL) injury without reconstruction has demonstrated inconsistent clinical success. PURPOSE:/UNASSIGNED:To examine the long-term clinical outcomes of primary ACL repair combined with biologic healing augmentation in patients with symptomatic partial ACL tears. STUDY DESIGN:/UNASSIGNED:Case series; Level of evidence, 4. METHODS:/UNASSIGNED:50 patients (mean age, 29.5 years) with a partial ACL tear and symptomatic knee instability were treated with primary ligament repair in conjunction with marrow stimulation and followed prospectively for a mean duration of 10.2 years (range, 5.3-14.3 years). Comparative analysis of preinjury, preoperative, and postoperative scores using patient-reported assessment instruments was performed to examine clinical outcomes. Correlation of final outcome scores with patient age, type of ACL tear, side-to-side difference in ligamentous laxity, and body mass index (BMI) was performed through use of Spearman rank analysis. RESULTS:/UNASSIGNED:= -0.376, P = .013). The mean side-to-side difference in ligamentous laxity of 3.4 mm at short-term follow-up in those patients who developed secondary ACL insufficiency over the duration of follow-up was significantly greater than the mean of 0.9 mm in those who did not ( P = .010). CONCLUSION:/UNASSIGNED:Primary ACL repair combined with biologic healing augmentation to treat select cases of knee instability secondary to incomplete ACL rupture demonstrated good to excellent long-term outcomes in this cohort for those patients who did not experience secondary ACL insufficiency, with high rates of restoration of knee stability and return to preinjury athletic activities. The rate of secondary treatment for recurrent ACL insufficiency over the course of long-term follow-up was greater than would be expected for primary ACL reconstruction. Greater side-to-side differences in objective findings of ligamentous laxity were identified at shorter term follow-up in the patients who later went on to experience symptomatic secondary ACL insufficiency, compared with those who maintained stability long term.

Articular cartilage damage to the acetabulum is frequently associated with femoroacetabular impingement, and there are considerable long-term implications for such injury with regard to maintenance of a healthy hip joint and quality of life. Developing treatments capable of restoring articular cartilage to acetabular cartilage defects is of great importance if hip preservation treatments are to be successful. Ideally, such methods should be performed in a minimally invasive manner and be capable of restoring durable repair tissue that reconstitutes a healthy osteochondral unit and that continues to function effectively over the long term.

The mechanical properties of cells influence their cellular and subcellular functions, including cell adhesion, migration, polarization, and differentiation, as well as organelle organization and trafficking inside the cytoplasm. Yet reported values of cell stiffness and viscosity vary substantially, which suggests differences in how the results of different methods are obtained or analyzed by different groups. To address this issue and illustrate the complementarity of certain approaches, here we present, analyze, and critically compare measurements obtained by means of some of the most widely used methods for cell mechanics: atomic force microscopy, magnetic twisting cytometry, particle-tracking microrheology, parallel-plate rheometry, cell monolayer rheology, and optical stretching. These measurements highlight how elastic and viscous moduli of MCF-7 breast cancer cells can vary 1,000-fold and 100-fold, respectively. We discuss the sources of these variations, including the level of applied mechanical stress, the rate of deformation, the geometry of the probe, the location probed in the cell, and the extracellular microenvironment.

PURPOSE/OBJECTIVE:To examine the quality of arthroscopic cartilage debridement using a curette technique by comparing regional and morphologic variations within cartilage lesions prepared in human cadaveric knee specimens for the purpose of cartilage repair procedures. A secondary aim was to compare the histologic properties of cartilage lesions prepared by surgeons of varying experience. METHODS:Standardized cartilage lesions (8 mm × 15 mm), located to the medial/lateral condyle and medial/lateral trochlea were created within 12 human cadaver knees by 40 orthopaedic surgeons. Participants were instructed to create full-thickness cartilage defects within the marked area, shouldered by uninjured vertical walls of cartilage, and to remove the calcified cartilage layer, without violating the subchondral plate. Histologic specimens were prepared to examine the verticality of surrounding cartilage walls at the front and rear aspects of the lesions, and to characterize the properties of the surrounding cartilage, the cartilage wall profile, the debrided lesion depth, bone sinusoid access, and the bone surface profile. Comparative analysis of cartilage wall verticality measured as deviation from perpendicular was performed, and Spearman's rank correlation analysis was used to examine associations between debrided wall verticality and surgeon experience. RESULTS: = -0.071, P = .419). CONCLUSIONS:Arthroscopic cartilage lesion preparation using standard curette technique in a human cadaveric knee model results in inferior perpendicularity of the surrounding cartilage walls at the front aspect of the defect, compared to the rear aspect. This technique has shown significant variability in the depth of debridement, with debridement depths identified as either too superficial or too deep to the calcified cartilage layer in more than 60% of cases in this study. Surgeon experience does not appear to impact the morphologic properties of cartilage lesions prepared arthroscopically using ring curettes. CLINICAL RELEVANCE: To optimize restoration of hyaline-like cartilage tissue, careful attention to prepared cartilage lesion morphology is advised when arthroscopically performing cartilage repair, given the tendency for standard curette technique to create inferior verticality of cartilage walls at the front of the lesion, and the variable depth of debridement achieved.

BACKGROUND:Cartilage lesion preparation is an important component to cartilage repair procedures, given the effect of prepared lesion morphology on the formation of durable and well-integrated repair tissue. PURPOSE/OBJECTIVE:To compare the quality of arthroscopic cartilage lesion debridement performed by (1) the standard curette (SC) technique and (2) specialized chondrectomy (CM) instruments, to provide technical guidance for optimization of cartilage lesion preparation in the setting of arthroscopic cartilage repair. STUDY DESIGN/METHODS:Controlled laboratory study. METHODS:Articular cartilage lesions of standardized size (8 × 15 mm) were demarcated within the trochlea and femoral condyles of 20 human cadaver knee specimens. Orthopaedic surgeons performed arthroscopic lesion preparation using 2 techniques that consisted of SC preparation and preparation by CM instruments. A histologic comparative analysis was performed within each treatment group and between treatment groups to evaluate the morphology of prepared cartilage defects. RESULTS:The mean angle deviation from perpendicular of the cartilage wall at the front of the prepared cartilage lesions was significantly greater in the SC group versus the CM group (29.8° ± 21.4° vs 7.7° ± 7.6°, P < .001). In lesions prepared via the SC technique, the cartilage walls at the front of the prepared lesions were significantly less perpendicular than the cartilage walls at the rear of the lesions (29.8° ± 21.4° vs 11.0° ± 10.3°, P < .001), whereas lesions prepared by the CM technique demonstrated comparable verticality of surrounding cartilage walls at the front and rear aspects of the lesions (7.7° ± 7.6° vs 9.4° ± 12.3°, P = .827). Depth of lesion debridement was accomplished to the target level by the CM technique in 86% of prepared lesions, compared with 34% of lesions in the SC group. The prepared cartilage wall profile was characterized as the most ideal morphology in 55% of prepared lesions in the CM group, as opposed to 10% in the SC group. CONCLUSION/CONCLUSIONS:Arthroscopic cartilage lesion preparation with SC instruments results in superior perpendicularity of surrounding cartilage walls to subchondral bone and greater consistency of debrided lesion depth, as compared with the standard debridement technique with curettes. CLINICAL RELEVANCE/CONCLUSIONS:Arthroscopic preparation using standard curette technique leads to suboptimal morphologic characteristics of prepared lesions that likely affect the quality of repair tissue, compared to preparation using specialized chondrectomy instruments.