Lee D. Kaplan

The Acute Effects of Radiofrequency Energy in Articular Cartilage: An In Vitro Study

SUMMARY The purpose of this investigation was to determine the acute effect of radiofrequency (RF) energy on articular cartilage. Six fresh human articular cartilage specimens were obtained from patients undergoing total knee arthroplasty for unicompartmental osteoarthritis. A jig was used as the RF-energy was delivered to 2 designated treatment areas. These areas included a normal and a diseased area of articular cartilage tested at 3 voltage settings (kilohertz per voltage root mean square), 133 to 147 (setting 2), 161 to 179 (setting 4), and 190 to 210 (setting 6) for 3 seconds. The designated testing areas were marked with tissue dye and processed using standard histological techniques. A scalloped concave excavation with a smooth surface remains at each treatment site. The chondrocytes are viable at the RF-treated sites without alterations in nuclear cytoplasmic nor lacunae structure when compared with collateral untreated areas. In conclusion, chondrocytes remain viable, no collagen abnormalities are detected, and diseased areas are smoothed without further evidence of fibrillation. RF-energy appears to be safe for use on articular cartilage.

Trends in Anterior Cruciate Ligament Reconstruction in the United States

Background: The anterior cruciate ligament (ACL) is the most frequently injured ligament in the knee for which surgery is performed. United States national estimates of ACL reconstruction vary widely. Purpose: This study sought to use the most recently available Centers for Disease Control and Prevention data to investigate changes in the utilization of inpatient and ambulatory surgery for ACL tears in the United States. Study Design: Descriptive epidemiology study. Methods: The National Survey of Ambulatory Surgery, conducted in 1994, 1995, 1996, and 2006 (data from 1994, 1996, and 2006 were used in the study), and the National Hospital Discharge Survey, conducted between 1990 and 2007, were used to identify cases of ACL reconstruction. The data were analyzed for trends in demographics, treatment, and utilization. Results: Between 1994 and 2006, the population-adjusted estimate of the rate of ACL reconstructions increased by 37% (33.0/100,000 capita or 86,837 total procedures to 45.1/100,000 capita or 134,421 total procedures). There was an increase in the proportion of females undergoing reconstruction in both the ambulatory (30% to 40%) and inpatient (29% to 47%) settings over the study period, with a 304% increase in the sex-adjusted estimate of the rate of female ambulatory procedures between 1994 and 2006. Age-adjusted estimates of the rates of ambulatory ACL reconstruction increased among all age groups, with a 924% increase in patients less than 15 years of age. Concurrent meniscectomy remained relatively constant in the ambulatory (37% to 40%) and inpatient (37% to 33%) settings between 1994 and 2007. Private insurance was the largest compensator, representing 77% of cases in 2006. Between 1994 and 2006, the use of peripheral nerve blocks during ambulatory surgery increased from 0.7% to 30.8%. Conclusion: The rate of ACL reconstruction increased dramatically between 1990 and 2007 based on the National Survey of Ambulatory Surgery and National Hospital Discharge Survey databases, which represents the most up-to-date publicly available data. Knowledge of this increase and national practice patterns may aid policy makers and surgeons in appropriately allocating health care resources to ensure quality patient care.

Mesenchymal Stem Cell Therapies in the Treatment of Musculoskeletal Diseases

The application of regenerative strategies to musculoskeletal ailments offers extraordinary promise to transform management of the conditions of numerous patients. The use of cell-based therapies and adjunct strategies is under active investigation for injuries and illnesses affecting bones, joints, tendons, and skeletal muscle. Of particular interest to the field is the mesenchymal stem cell, an adult stem cell found in bone marrow and adipose tissue. This cell type can be expanded ex vivo, has allogeneic application, and has the capacity for engraftment and differentiation into mesodermal lineages. Also of major interest in the field is the use of platelet-rich plasma, a strategy to concentrate endogenous cytokines and growth factors with reparative potential. Here we review the biological basis, clinical studies, safety, and current state of mesenchymal stem cell and platelet-rich plasma therapies in the treatment of musculoskeletal disease.

Glenohumeral Findings on Magnetic Resonance Imaging Correlate With Innings Pitched in Asymptomatic Pitchers

Background: In recent years, there has been a documented increase in the number of professional baseball players on the disabled list and the total number of days on the disabled list. Pitchers account for the largest number of disabled list reports. Purpose: To examine the relationship between magnetic resonance imaging (MRI) findings in asymptomatic professional pitchers and subsequent time on the disabled list (DL). Study Design: Cohort study (Prognosis); Level of evidence, 2. Methods: A total of 21 asymptomatic professional pitchers from a single Major League Baseball (MLB) organization underwent preseason MRIs of their dominant shoulder from 2001 to 2010. Asymptomatic was defined as no related DL stays in the 2 seasons before the MRI. These studies were reevaluated by a fellowship-trained musculoskeletal radiologist who was blinded to patient name, injury history, and baseball history. A second investigator who was blinded to the MRI results collected demographic data, total career number of innings pitched, and any subsequent DL reports for each subject. Results: The mean age at the time of MRI was 29.04 years (range, 20-39 years). Eleven of 21 pitchers had a rotator cuff tear (RCT): 9 had an articular surface tear (AST), and 2 had a full-thickness rotator cuff tear (FTT). Ten had superior labral anterior posterior (SLAP) tears, and 13 had either anterior or posterior labral tears. There was a statistically significant relationship between the number of innings pitched and presence of an RCT (AST + FTT). The mean number of career innings pitched by those with an RCT was 1014 compared with a mean of 729 innings pitched in pitchers without an RCT (P < .01). In addition, the number of career innings pitched was moderately correlated with presence of RCT (r = 0.46) and presence of superior and anterior/posterior labral tears (r = 0.43). There were no statistically significant findings between any single preseason MRI finding and subsequent time on the DL. Conclusion: The MRI findings in asymptomatic MLB pitchers do not appear to be related to near future placement on the DL. However, there was a significant difference in numbers of innings pitched between pitchers who had an RCT and those who did not and a moderate correlation between innings pitched and the presence of RCT as well as the presence of labral lesions. This finding supports the notion that RCT and labral injury in pitchers may result from repetitive overhead motion with subsequent strain on the rotator cuff tendons and glenoid labrum. Asymptomatic shoulder lesions in professional baseball pitchers appear to be more frequent than previously thought.

A Biomechanical Comparison of Fan-Folded, Single-Looped Fascia Lata With Other Graft Tissues as a Suitable Substitute for Anterior Cruciate Ligament Reconstruction

PURPOSE The purpose of this study was to evaluate the initial biomechanical properties of a fan-folded, single-loop construct of fan-folded fascia lata allograft in comparison to other graft tissues currently being used for anterior cruciate ligament (ACL) reconstruction. METHODS Eighteen fascia lata specimens were harvested from 11 donors and fan folded through a proprietary process. Bone-patellar tendon-bone (BPTB), tibialis anterior, tibialis posterior, and peroneus longus tendons were harvested from 4 additional donors. All soft-tissue grafts were tested to failure in an MTS machine (MTS Systems, Eden Prairie, MN) in a single-looped fashion. BPTB grafts were similarly clamped in freeze grips. The ultimate load to failure and stiffness were calculated for each graft type tested. RESULTS The mean ultimate load to failure was 3,266 N and stiffness was 414 N/mm for the single-looped fascia lata grafts (n = 18). There was no significant difference for ultimate load to failure and stiffness between the fascia lata and tibialis anterior (3,012 N and 342 N/mm, respectively), tibialis posterior (3,666 N and 392 N/mm, respectively), and peroneus longus (3,050 N and 346 N/mm, respectively) tendons. The fascia lata grafts performed significantly better (P < .001) than BPTB (1,404 N and 224 N/mm, respectively). CONCLUSIONS A single-loop construct of fan-folded fascia lata allograft has, on biomechanical testing, initial ultimate tensile strength (3,266 N) and stiffness values equivalent to or better than several other graft tissues currently used in ACL reconstruction, including BPTB (1,403 N), tibialis anterior (3,012 N), tibialis posterior (3,666 N), and peroneus longus (3,050 N). CLINICAL RELEVANCE In the face of potential allograft tissue shortages and increasing constraints on health care expenditures, the use of fascia lata has the potential to be a readily available graft for ACL reconstruction that performs as well as other grafts and at a comparable or lower cost.

Ultrasound-guided aspiration of symptomatic intraneural ganglion cyst within the tibial nerve

Intraneural ganglia are rare non-neoplastic cysts caused by the accumulation of thick mucinous (mucoid) fluid within the epineurium of peripheral nerves, encased in a dense fibrous capsule [1, 2]. These cysts cause compression of adjacent nerve fascicles, resulting in leg paresthesias, pain, weakness, muscle denervation, and atrophy [3]. The peroneal (fibular) nerve at the level of the fibular neck is most commonly affected [4–6]. Involvement of other peripheral nerves surrounding articular surfaces (including the radial, ulnar, median, sciatic, tibial and posterior interosseous nerves) has been previously described [6–21]. Tibial intraneural ganglia in the knee region are particularly rare, with fewer than 15 reported cases in the literature [2, 8–15]. Although their ultrasound (US) and magnetic resonance imaging (MRI) appearance has been previously documented [8–15, 22], to our knowledge no one has reported the ultrasound-guided aspiration of a symptomatic intraneural ganglion cyst within the tibial nerve.

Inflammatory cytokines induce specific time‐ and concentration‐dependent microRNA release by chondrocytes, synoviocytes and meniscus cells

In knee osteoarthritis (OA), concentrations of interleukin (IL)‐1β and tumor necrosis factor (TNF)‐α increase in joint tissues and synovial fluid which incite a catabolic cascade and further the progression of OA. Several microRNAs (miRNA) have been associated with apoptosis (miR‐16), inflammation (miR‐22, miR‐146a), and matrix degradation (miR‐140, miR‐27b) in developed OA or its symptoms. In this study, the time‐ and concentration‐dependent nature of cellular and extracellular miRNAs in synoviocytes, meniscus cells, and chondrocytes as influenced by inflammatory cytokines was investigated. For time‐dependent studies, three cell types were stimulated with 10 ng/ml IL‐1β or 50 ng/ml TNF‐α for 8, 16, and 24 h. For concentration‐dependent studies, chondrocytes were stimulated with a higher level of IL‐1β (20 ng/ml) or TNF‐α (100 ng/ml) for 8 h. Cellular and extracellular expressions of miR‐22, miR‐16, miR‐146a, miR‐27b, and miR‐140 were analyzed by RT‐PCR. Time‐dependent cellular miRNA expressions were similar across the three cell types with miR‐146a significantly up‐regulated and miR‐27b significantly down‐regulated at all time points. However, chondrocytes exhibited a unique extracellular miRNA profile with an increased release rate of miR‐27b at 24 h. Our findings support further research into the characterization of miRNAs in synovial fluid for the development of early detection strategies of OA or cartilage injury.

Rates and Determinants of Return to Play after Anterior Cruciate Ligament Reconstruction in Division 1 College Football Athletes: A Study of the ACC, SEC, and PAC-12

Background: For competitive athletes, return to play (RTP) and return to preinjury levels of performance after anterior cruciate ligament (ACL) reconstruction are the main goals of surgery. Although outcomes of ACL surgery are well studied, details on factors influencing RTP in elite college football players have not been evaluated thoroughly. Purpose: To determine the rate of RTP following ACL surgery among National Collegiate Athletic Association (NCAA) Division 1 collegiate football athletes and to examine variables that may affect these rates. The hypothesis was that the RTP rate in this cohort will be influenced by factors reflecting skill and accomplishment; that is, athletes higher on the depth chart, those on scholarship, and those later in their careers will have higher RTP rates. It was also predicted that graft type and concomitant procedures may have an effect on RTP rates. Study Design: Case series; Level of evidence, 4. Methods: Using athlete- and surgery-specific data from participating institutions in 3 major Division 1 college football conferences, information on athletes who had ACL reconstruction from 2004 through 2010 was collected. Statistical analyses were performed to determine the RTP rate as a function of the variables, such as depth chart position, in the data collected. Results: Of the 184-player cohort, 82% of the athletes, including 94% of starters, were able to RTP. Rates were greater among athletes higher on the depth chart (P = .004) and on scholarship (P = .008). Year of eligibility also affected RTP rates (P = .047), which increased from the redshirt and freshman year to the sophomore and junior years, but then decreased slightly into the senior and fifth-year senior seasons. The use of an autograft versus allograft was associated with increased RTP (P = .045). There was no significant difference (P = .18) between players who underwent an isolated ACL reconstruction versus those who underwent additional procedures. Conclusion: More than 80% of football players at the Division 1 level were able to RTP following ACL reconstruction. Factors representative of a player’s skill were associated with higher rates of RTP. Surgery-specific variables, in general, had no effect on RTP, except for the use of autograft, which was associated with a greater RTP rate.

Anterior cruciate ligament injury and access to care in South Florida: does insurance status play a role?

BACKGROUND Health insurance status and access to care are recurring topics of discussion and concern. The purpose of this investigation was to examine access to care on the basis of insurance status for patients with anterior cruciate ligament (ACL) injuries in South Florida. METHODS From March 2010 to March 2011, eighty patients with ACL injuries were identified at a county hospital sports medicine clinic and a university-based sports medicine practice. Demographic and injury-specific data were obtained with attention to the date of injury, the date of diagnosis, and the number of medical visits. Hazard ratios and 95% confidence intervals were calculated from multivariable Cox proportional-hazards regression models to determine the effect of insurance type on the time to diagnosis of an ACL tear. RESULTS Patients with private insurance were diagnosed at a median fourteen days after the injury, whereas those receiving Medicaid and those without insurance were diagnosed a median of fifty-six and 121 days after the injury, respectively (p < 0.001). Patients without insurance and those receiving Medicaid had more medical visits prior to diagnosis (median, four; range two to six) than those with private insurance (median, three; range, one to five) (p = 0.006). Differences for patient delays due to not seeking care were not significant among the three groups (p = 0.484). CONCLUSIONS When grouped according to insurance status, subjects receiving Medicaid in South Florida faced greater system-related delays in obtaining care than did subjects with private insurance. System-related factors such as lack of access to specialized care result in an increased number of medical encounters. These regional findings are consistent with those of other regional studies on access to orthopaedic care.

Metabolic activity of osteoarthritic knees correlates with BMI

Osteoarthritis of the knee has consistently been linked to obesity, defined as a body mass index (BMI) >30kg/m(2). It has been hypothesized that obesity may lead to osteoarthritis through increased joint pressure, accumulated microtrauma, and disruption of normal chondrocyte metabolism. These changes in chondrocyte metabolism have not been thoroughly investigated, and it is the purpose of this study to identify a relationship between BMI and altered chondrocyte metabolism in osteoarthritic tissue. Articular cartilage was harvested from the femoral condyles of patients after total knee arthroplasty, and analyzed in explant and alginate models. Glycosaminoglycan (GAG) content was measured using a dimethylmethylene blue assay and normalized to DNA content using a PicoGreen(R) assay. Studies have reported GAGs to be a reliable measurement of chondrocyte metabolism and osteoarthritis progression. Our results show a significant linear relationship of increasing BMI and increasing GAG content in both alginate and explant models (p<0.001 and p=0.001). Obese (BMI>/=30kg/m(2)) and non-obese (BMI<30kg/m(2)) comparisons also demonstrated significant differences with higher GAG/DNA content in obese individuals compared to non-obese (p=0.001 and p=0.015). The study results reveal significant relationships between GAG content and BMI in this population of osteoarthritic patients. The significant difference in GAG content between the obese and non-obese patients supports the connection between osteoarthritis and obesity previously reported. Higher patient BMI (>30kg/m(2)) may be similar to dynamic compression injuries which cause increased GAG synthesis in response to cartilage damage.