Faculty Bibliography

BACKGROUND:Tissue excision in the setting of a meniscal tear has been shown to dramatically increase peak contact stresses in the affected tibiofemoral joint compartment, leading to the development of degenerative changes and osteoarthritis. PURPOSE/HYPOTHESIS/UNASSIGNED:The current in vitro study utilized a porcine model to evaluate the effectiveness of segmental medial meniscal grafting following partial meniscectomy. The study hypothesis was that the procedure would normalize medial tibofemoral joint compartment pressure magnitudes, areas, and locations relative to an intact meniscus. STUDY DESIGN/METHODS:Controlled laboratory study. METHODS:Using pressure film, medial tibiofemoral joint compartment peak, and mean pressure magnitudes, peak pressure location and peak pressure area were determined using 12 potted, fresh frozen, porcine knee specimens. Data were collected at three different knee flexion angles (90°, 45°, and 0°) for three conditions: intact medial meniscus, following resection of the central third of the medial meniscus, and following segmental medial meniscal grafting. For each condition, the potted femur was positioned horizontally in a bench vise clamp, while a 20 pound (88.96 N) axial compression force was manually applied for a 60 s duration by the primary investigator through the base of the potted tibia using a digital force gauge. RESULTS:Loss of the central 1/3 of the medial meniscus resulted in significant increases in the mean and peak pressures of the medial tibiofemoral joint compartment and decreased peak pressure area. Segmental meniscal grafting of the central third defect closely recreated the contact pressures and loading areas of the native, intact medial meniscus. CONCLUSION/CONCLUSIONS:From a static, time zero biomechanical perspective, segmental medial meniscus grafting of a partially meniscectomized knee restored mean pressure, peak pressure, and mean peak contact pressure areas of the medial tibiofemoral joint compartment back to levels observed in the intact medial meniscus at different knee flexion angles. In-vivo analysis under dynamic conditions is necessary to verify the healing efficacy and ability of the healed segmental medial meniscal allograft to provide long-term knee joint homeostasis when confronted with dynamic shear, rotatory, and combined, higher magnitude physiologic loading forces.

Over recent years, appreciation for the critical role of the meniscus in joint biomechanics has led to an emphasis on meniscal preservation. Meniscal allograft transplant (MAT) is a promising biological solution for the symptomatic young patient with a meniscus-deficient knee that has not developed advanced osteoarthritis. As surgical techniques are refined and outcomes continue to improve, it is vital to consider the utility of such procedures and offer a straightforward approach to MAT. This article and accompanying video provide a step-by-step tutorial on how to perform a MAT using the bridge and slot technique, its key pearls and pitfalls as well as the relevant advantages and disadvantages of MAT.

PURPOSE: Injury to the anterolateral ligament (ALL) of the knee has recently received attention as a potential risk factor for failure of anterior cruciate ligament reconstruction. However, evaluation of the anterolateral ligament is currently difficult, and radiologic data are sparse with regard to the normal appearance of this ligament. The purpose of the present study was to determine whether the ALL could be identified and visualized using ultrasonography. METHODS: Ten non-paired, fresh-frozen cadaveric knees underwent ultrasound by an experienced musculoskeletal radiologist using a Siemens S2000 Acuson Ultrasound machine with a 14-MHz linear transducer. After first identifying anatomical landmarks by palpation, a thin band of tissue originating in the vicinity of the fibular collateral ligament (FCL) origin was identified and followed up distally. The tibia was held at 30 degrees of flexion and internally rotated to verify tightening of the structure. Under ultrasound guidance, 25-gauge hypodermic needles were placed at what were sonographically determined to be the origin and insertion points of the ligament. One-tenth of a CC of aniline blue dye was injected. The specimens were then dissected to confirm the presence and location of the ALL. If an ALL was found, distances between the epicentre of the injected dye and the actual origin and insertion points were calculated. Additionally, ligament length based on dissection images and ultrasound images was calculated. RESULTS: Eight of ten specimens had an anterolateral structure that originated from the lateral femoral epicondyle just posterior and superior to the origin of the FCL and inserted on the lateral plateau approximately halfway between Gerdy's tubercle and the fibular head. The average length based on ultrasound was 3.8 cm (+/-.7; range 3.1-4.7) and 4.1 cm (+/-1.1; range 2.6-6.1) based on dissection. Length based on dissection and ultrasound had minimal agreement (ICC = .308; 95 % confidence interval .257-.382, p = .265). The average width of the structure on dissection was .8 cm (+/-.24; range .5-1.2). The mean distance from ultrasound-determined origin and insertion points to anatomical origin and insertion based on dissection was 10.9 mm (+/-2.9, range 7.0-15.8) and 12.5 mm (+/-5.7 range 3.2-19.3), respectively. Inter-observer reliability was excellent for all measurements based on dissection and ultrasound. CONCLUSION: Ultrasound was unable to reliably identify the anterolateral structure from its femoral to tibial attachment sites. Distinguishing it from the posterior IT band and anterolateral capsule was challenging, and it is possible that the structure is a thickened band of fascia rather than a true ligament. As a clinical diagnostic tool, ultrasound likely offers little utility in the evaluation of the ALL for injury. LEVEL OF EVIDENCE: IV.

Objectives: Continuous gradient-echo (GRE) acquisition or "dynamic magnetic resonance imaging", allows for high-speed examination of pathologies based on joint motion. We sought to assess the efficacy of a radial GRE sequence with in the characterization of patellofemoral maltracking. Methods: Patients with suspected patellofemoral maltracking and asymptomatic volunteers were scanned using GRE (Siemens LiveView WIP; Malvern, PA, USA) at 3T in the axial plane at the patella level through a range of flexion-extension (0-30degree). The mean time to perform the dynamic component ranged from 3-7 mins. Lateral maltracking (amount patella moved laterally through knee ranging) was measured. Patella lateralization was categorized as normal (<= 2mm), mild (2-5mm), moderate (5-10mm), or severe (>10mm). Tibial tuberosity: trochlear groove (TT: TG) distance, trochlea depth, Insall-Salvati ratio, and patellofemoral cartilage quality (according to the modified Outerbridge grading system) were also assessed. Results: Eighteen symptomatic (6 men; 12 women, age range 14-51 years) and 10 asymptomatic subjects (6 men; 4 women, age range 25-68 years) were included. Two symptomatic patients underwent bilateral examinations. Lateralization in the symptomatic group was normal (n=10), mild (n=2), moderate (n=5) and severe (n=3). There was no abnormal maltracking in the volunteer group. Lateral tracking significantly correlated with TT: TG distance (F=38.0; p<.0001), trochlea depth (F=5.8; p=.023), Insall-Salvati ratio (F=4.642; p=.04) and Outerbridge Patella score (F=6.6; p=.016). Lateral tracking did not correlate with Outerbridge Trochlear score. Conclusion: Lateral tracking measured on GRE was found to significantly correlate with current measures of patellar instability including, TT: TG, trochlea depth, and the Insall-Salvati ratio. GRE is a rapid and easily performed addition to the standard protocol for kinematic patellofemoral motion and can add dynamic information on patellofemoral tracking. This may be help determine if an isolated MPFL or an MPFL reconstruction and tibial tubercle osteotomy is needed to treat patella instability

PURPOSE: To investigate the biomechanical properties of the load shifting following opening-wedge distal femoral varus osteotomies (DFVOs) and determine the osteotomy correction needed to unload the lateral compartment. METHODS: Five human cadaveric knees were tested with a load of 500 N of axial compression. Medial and lateral tibiofemoral compartment contact area and pressure were assessed utilizing a modified F-scan pressure-sensitive sensor. The knees were tested in their baseline anatomic alignment, 10 degrees valgus malalignment and following corrective DFVOs of 5 degrees , 10 degrees and 15 degrees . The load shifting effect of the various DFVO correction angles was analysed using a one-way ANOVA to determine the correction angle necessary to unload the lateral compartment. RESULTS: Gradually shifting the loading vector medially with increasing DFVO angles resulted in a decrease in the mean contact area and mean contact pressures in the lateral compartment with progressive increases in the medial compartment. The largest reduction in lateral compartment pressure and contact area was seen with the 15 degrees osteotomy with a 25 % decrease in mean contact pressure and 20 % decrease in mean maximum contact pressure and mean contact area when compared to the 10 degrees valgus-malaligned knee. For the 10 degrees valgus knee, a 15 degrees correction resulted in near-normal contact pressures and areas compared with the knee in normal anatomic alignment. CONCLUSION: Progressive unloading of the lateral tibiofemoral compartment occurred with increasing DFVO correction angles. Clinically, when performing a DFVO for valgus malalignment, surgeons should consider overcorrecting the osteotomy by 5 degrees to restore near-normal contact pressures and contact areas in the lateral compartment rather than the traditional teaching of correcting to neutral alignment.

PURPOSE:The aims of the study were as follows: (1) to perform a systematic review of meta-analyses evaluating platelet-rich plasma (PRP) use at the time of arthroscopic rotator cuff repair surgery and to determine its effect on retear rates and clinical outcomes; (2) to provide a framework for the analysis and interpretation of the best currently available evidence; and (3) to identify gaps within the literature where suggestions for continued investigational efforts would be valid. METHODS:Literature searches were performed to identify meta-analyses examining arthroscopic rotator cuff repairs augmented with PRP versus control (no PRP). Clinical data were extracted and meta-analysis quality was assessed using the Quality of Reporting of Meta-analyses and Oxman-Guyatt scales. RESULTS:Seven meta-analyses met inclusion and exclusion criteria. All were considered as being of similar quality with Quality of Reporting of Meta-analyses scores >15 and Oxman scores of 7. A total of 3,193 overlapping patients treated were included with mean follow-up from 12 to 31 months. When compared with control patients, use of PRP at the time of rotator cuff repair did not result in significantly lower overall retear rates or improved clinical outcome scores. The following postoperative functional scores comparing PRP versus control were reported: Constant (no significant difference demonstrated with PRP use in 5 of 6 reporting meta-analyses), University of California - Los Angeles (no difference, 6 of 6), American Shoulder and Elbow Society (no difference, 4 of 4), and Simple Shoulder Test (no difference, 3 of 5). Subgroup analysis performed by 3 meta-analyses showed evidence of improved outcomes with solid PRP matrix versus liquid, small- and/or medium-sized versus large and/or massive tears, PRP application at the tendon-bone interface versus over tendon, and in the setting of double-row versus single-row rotator cuff. CONCLUSIONS:The current highest level of evidence suggests that PRP use at the time of arthroscopic rotator cuff repair does not universally improve retear rates or affect clinical outcome scores. However, the effects of PRP use on retear rates trend toward beneficial outcomes if evaluated in the context of the following specific variables: use of a solid PRP matrix; application of PRP at the tendon-bone interface; in double-row repairs; and with small- and/or medium-sized rotator cuff tears. LEVEL OF EVIDENCE:Level III, systematic review of Level II and III studies.

Anterior cruciate ligament (ACL) rupture is a common injury that mostly affects young adults. The mechanisms of injury and surgical treatment have been extensively studied in both the laboratory and clinical arenas; however, great controversy still exists in regards to the best surgical technique, graft choice, and graft fixation device. In the area graft fixation, multiple breakthroughs have occurred in terms of fixation devices. These devices generally fall within the broad categories of interference screw, cross-pins, or cortical-based devices. Furthermore, some of these devices are available in either metal or bioabsorbable materials, which adds to the already great variety of options. Although biomechanically these devices have been shown to be able to withstand the typical forces experienced by the ACL graft during the early phases of rehabilitation before the graft has fully incorporated into the bone, little is known about the clinical outcomes. It is well recognized that graft fixation is the weakest link in the early postoperative period after ACL reconstruction. This review of the outcomes of ACL fixation devices explores some of the evidence available for the different devices.

The incidence of anterior cruciate ligament (ACL) patients has doubled in the past 5 years at Rush University Orthopaedics. Additionally, there has been a 3-fold increase in the number of anterior cruciate ligament injuries in patients younger than the age of 25 years of age during this 5-year period. Fortunately, approximately 80%-90% of these patients return to their sports at their previous level of play. However, with the increased incidence in tears, it is important for medical providers to assist the patients in determining the risk factors they may display when preparing to return to sport. There are very few published return to sport guidelines following anterior cruciate ligament reconstruction. Midwest Orthopaedics at Rush has developed a functional sports assessment (FSA) to evaluate anterior cruciate ligament injury risk factors on postoperative patients. The FSA factors include range-of-motion, strength, endurance, proprioception, power, core stability, ankle stability, and overall biomechanics and confidence. Although the FSA has not been proven reliable or valid, it is based on the other commonly used tasks in determining a patient's ability after anterior cruciate ligament surgery. It has been clinically relevant for the patient, therapist, athletic trainer, and physician in identifying weaknesses and risk factors at the 5-6 month time postoperative time period. This helps to guide the patient in what tasks he or she needs to be attentive to during the transition to return to sport to minimize reinjury. This article provides factors that were considered when developing the FSA, a detailed description of the FSA, and future considerations to improve the assessment for validity and reliability. Oper Tech Sports Med 24:59-64 (C) 2015 Elsevier Inc. All rights reserved.