Amgad M. Haleem

Establishing proof of concept: Platelet-rich plasma and bone marrow aspirate concentrate may improve cartilage repair following surgical treatment for osteochondral lesions of the talus

Osteochondral lesions of the talus are common injuries in the athletic patient. They present a challenging clinical problem as cartilage has a poor potential for healing. Current surgical treatments consist of reparative (microfracture) or replacement (autologous osteochondral graft) strategies and demonstrate good clinical outcomes at the short and medium term follow-up. Radiological findings and second-look arthroscopy however, indicate possible poor cartilage repair with evidence of fibrous infill and fissuring of the regenerative tissue following microfracture. Longer-term follow-up echoes these findings as it demonstrates a decline in clinical outcome. The nature of the cartilage repair that occurs for an osteochondral graft to become integrated with the native surround tissue is also of concern. Studies have shown evidence of poor cartilage integration, with chondrocyte death at the periphery of the graft, possibly causing cyst formation due to synovial fluid ingress. Biological adjuncts, in the form of platelet-rich plasma (PRP) and bone marrow aspirate concentrate (BMAC), have been investigated with regard to their potential in improving cartilage repair in both in vitro and in vitro settings. The in vitro literature indicates that these biological adjuncts may increase chondrocyte proliferation as well as synthetic capability, while limiting the catabolic effects of an inflammatory joint environment. These findings have been extrapolated to in vitro animal models, with results showing that both PRP and BMAC improve cartilage repair. The basic science literature therefore establishes the proof of concept that biological adjuncts may improve cartilage repair when used in conjunction with reparative and replacement treatment strategies for osteochondral lesions of the talus.

The effect of platelet-rich plasma on autologous osteochondral transplantation: an in vivo rabbit model.

BACKGROUND Autologous osteochondral transplantation restores a cartilage defect with a cylindrical unit of bone and articular cartilage. Previous studies have described poor graft integration at the chondral interface and degeneration of the cartilage. This has prompted the investigation of adjuncts to address these concerns, including platelet-rich plasma (PRP), which has the potential to improve chondral interface integration and decrease cartilage degeneration. The purpose of this study was to evaluate the effect of PRP on autologous osteochondral transplantation in a rabbit model. METHODS Bilateral osteochondral defects (2.7 mm in diameter and 5 mm in depth) were created on the femoral condyles of twelve New Zealand White rabbits. Osteochondral grafts were harvested from the ipsilateral femoral condyle and, after randomization, were treated with either PRP or saline solution before implantation into the defect site. The rabbits were killed at three, six, or twelve weeks postoperatively. The osteochondral graft was assessed using the International Cartilage Repair Society (ICRS) macroscopic and modified ICRS histological scoring systems. RESULTS Macroscopic assessment revealed no significant difference between the two groups (mean and standard deviation, 11.2 ± 0.9 for the PRP-treated group versus 10.3 ± 0.9 for the control group; p = 0.09). The mean modified ICRS histological score was significantly higher overall and at each time point for the PRP-treated osteochondral transplants compared with the controls (overall mean, 18.2 ± 2.7 versus 13.5 ± 3.3; p = 0.002). Assessing graft integration specifically, the mean score for the PRP-treated group was significantly higher than that for the control group (2.5 ± 0.9 versus 1.6 ± 0.7; p = 0.004). No adverse events occurred as a result of the surgical procedure or PRP. CONCLUSIONS PRP may improve the integration of an osteochondral graft at the cartilage interface and decrease graft degeneration in an in vivo animal model. CLINICAL RELEVANCE The use of PRP as a biological adjunct to autologous osteochondral transplantation has the clinical potential to enhance graft integration, decrease cartilage degeneration, and improve clinical outcomes of autologous osteochondral transplantation.

Comparison of Deformity with Respect to the Talus in Patients with Posterior Tibial Tendon Dysfunction and Controls Using Multiplanar Weight-Bearing Imaging or Conventional Radiography

BACKGROUND Posterior tibial tendon dysfunction varies in location and severity. Weight-bearing radiographs have been validated to assess posterior tibial tendon dysfunction, yet their two-dimensional nature and the inability of the patients to achieve full weight-bearing during acquisition are limitations. Multiplanar modified sectional weight-bearing imaging is a novel modality, yielding computed tomography-like images compared with radiographs, yet with true weight-bearing, shorter acquisition time, and lower radiation. The aim of this study was to test two hypotheses: first, multiplanar weight-bearing imaging would localize deformity with respect to the talus in patients with posterior tibial dysfunction compared with controls, and second, multiplanar weight-bearing imaging would correlate with specific radiographic parameters of posterior tibial tendon dysfunction on weight-bearing radiographs. METHODS Weight-bearing radiographs and multiplanar modified sectional weight-bearing images of the foot and ankle were made for twenty-three patients with flexible posterior tibial tendon dysfunction. Ten patients with imaging for unrelated pathological conditions served as controls. Thirteen radiographic parameters on the transverse, sagittal, and coronal views of multiplanar weight-bearing imaging in the study group were evaluated and compared with those in the control group. The same parameters on standing weight-bearing radiographs of patients in the study group were compared with those in the control group. RESULTS Significant differences between study and control groups were found on multiplanar weight-bearing imaging for six of thirteen radiographic parameters (p < 0.05), notably the sagittal talonavicular angle as well as sagittal and transverse talar-first metatarsal angles (p = 0.027, p = 0.003, and p = 0.004, respectively). However, only one parameter on weight-bearing radiographs (lateral talar-first metatarsal angle) reached significance (p < 0.05). Correlation showed excellent, very good, and good agreement between both imaging modalities for three, two, and five parameters, respectively. CONCLUSIONS Deformity with respect to the talus in posterior tibial tendon dysfunction is multifactorial, but was notably seen at the talonavicular joint in the sagittal plane with both modalities. Good to excellent agreement was found between weight-bearing radiographs and multiplanar weight-bearing images for many parameters; however, a greater number of significant differences was found between the flatfoot and control groups for multiplanar weight-bearing images. This implies a potential role for multiplanar modified sectional weight-bearing imaging as a more informative tool to assess posterior tibial tendon dysfunction in the physiological, full weight-bearing position.

A Review of Synthetic Playing Surfaces, the Shoe-Surface Interface, and Lower Extremity Injuries in Athletes

Abstract The evolution of synthetic playing surfaces began in the 1960s and has had an impact on field use, shoe-surface dynamics, and the incidence of sports-related injuries. Modern third-generation turfs are being installed in recreational facilities and professional stadiums worldwide. Currently, > two-thirds of National Football League teams,> 100 National Collegiate Athletic Association Division I football teams, and > 1000 high schools in the United States have installed synthetic playing surfaces. Those in favor of such playing surfaces note their unique combination of versatility and durability; they can be used in both ideal and inclement weather conditions. However, the more widespread installation and use of these surfaces have raised questions and concerns regarding the impact of artificial turf on the type and severity of sports-related injuries. There appears to be no question that the shoe-surface interface has a significant impact on such injuries. Independent variables such as weather conditions, contact versus noncontact sport, shoe design, and field wear complicate many of the results reported in the literature, thereby preventing an accurate assessment of the true risk(s) associated with certain shoe-surface combinations. Historically, studies suggest that artificial turf is associated with a higher incidence of injury. Furthermore, reliable biomechanical data suggest that both the torque and strain experienced by lower extremity joints generated by artificial surfaces may be more than those generated by natural grass fields. Recent data from the National Football League support this theory and suggest that elite athletes may sustain more injuries, even when playing on the newer artificial surfaces. By contrast, some reports based on data collected from lower-level athletes suggest that artificial turf may protect against injury. This review discusses the history of artificial surfaces, the biomechanics of the shoe-surface interface, and some common turf-related lower extremity injuries.

Assessment of Coronal Plane Subtalar Joint Alignment in Peritalar Subluxation via Weight-Bearing Multiplanar Imaging

Background: Patients with adult-acquired flatfoot deformity (AAFD) develop peritalar subluxation, which may stem from valgus inclination of the inferior surface of the talus. We hypothesized that patients with AAFD would have an increased valgus tilt of the subtalar joint in the coronal plane compared to controls when assessed with a novel multiplanar weight-bearing imaging (MP-WB). Methods: Eighteen normal and 36 stage II AAFD patients scheduled to undergo operative reconstruction were evaluated by MP-WB through measuring 3 novel angles of the subtalar joint in the coronal view: (1) angle between inferior facet of the talus and the horizontal/floor (inftal-hor), (2) angle between inferior and superior facets of the talus (inftal-suptal), and (3) angle between inferior facet of the talus and superior facet of the calcaneus (inftal-supcal). Intra- and interobserver reliability were evaluated via intraclass correlation coefficients (ICCs). Differences in angles between AAFD patients and controls were evaluated using Wilcoxon rank-sum test. Results: Intra- and interobserver reliability were excellent for inftal-hor (ICC .942 and .991, respectively) and inftal-suptal (ICC .948 and .989, respectively), and moderate-good for inftal-supcal (ICC .604 and .742, respectively). Inftal-hor and inftal-suptal angles were found to be significantly greater in AAFD patients (P < 0.001) at all 3 locations along the posterior subtalar joint, while inftal-supcal did not demonstrate a significant difference (P = .741). While controls exhibited varus orientation at the anterior aspect of the joint, AAFD patients maintained a valgus orientation throughout. Conclusion: Inftal-hor and inftal-suptal angles provided a reliable means of evaluating the orientation of the subtalar joint axis in AAFD via MP-WB, and showed that the subtalar joint had increased valgus orientation in AAFD compared to controls. This may allow for identification of patients at risk for developing AAFD, and could potentially be used in guiding operative reconstruction. Level of Evidence: Level III, comparative series.

Synthetic Playing Surfaces and Athlete Health

&NA; Synthetic playing surfaces have evolved considerably since their introduction in the 1960s. Today, third‐generation turf is routinely installed in professional, collegiate, and community settings. Proponents of artificial surfaces tout their versatility and durability in a variety of climates. However, the health and injury ramifications have yet to be clearly defined. Musculoskeletal injury is largely affected by the shoe‐playing surface interface. However, conclusive statements cannot be made regarding the risk of certain shoe‐playing surface combinations because of the variety of additional factors, such as weather conditions, shoe wear, and field wear. Historically, clinical studies have indicated that higher injury rates occur on artificial turf than on natural surfaces. This conclusion is backed by robust biomechanical data that suggest that torque and strain may be greater on artificial surfaces than on natural grass. Recent data on professional athletes suggest that elite athletes may sustain injuries at increased rates on the newer surfaces. However, these surfaces remain attractive to athletes and administrators alike because of their durability, relative ease of maintenance, and multiuse potential.

Double-Plug Autologous Osteochondral Transplantation Shows Equal Functional Outcomes Compared With Single-Plug Procedures in Lesions of the Talar Dome A Minimum 5-Year Clinical Follow-up

Background: Autologous osteochondral transplantation (AOT) is used for large (>100-150 mm2) or cystic osteochondral lesions (OCLs) of the talus. Larger lesions may require using more than 1 graft to fill the defect. While patients with larger OCLs treated with microfracture exhibit inferior clinical outcomes, there is little evidence regarding the effect of lesion size and number of grafts required on clinical and radiological outcomes after AOT. Hypothesis: Larger OCLs of the talar dome treated by double-plug AOT (dp-AOT) have inferior clinical and radiological MRI outcomes compared with smaller OCLs requiring single-plug AOT (sp-AOT). Study Design: Cohort study; Level of evidence, 3. Methods: Fourteen consecutive patients with a large OCL (mean, 208 ± 54 mm2) treated using dp-AOT with a minimum 5-year follow-up were matched by age and sex to a control cohort of 28 patients who underwent sp-AOT for a smaller OCL (mean, 74 ± 26 mm2) over the same period. Functional outcomes were assessed both pre- and postoperatively using the Foot and Ankle Outcome Score (FAOS) and Short Form–12 (SF-12) general health questionnaire. Mean follow-up was 85 months (range, 65-118 months). Latest postoperative MRI was evaluated with modified magnetic resonance observation of cartilage repair tissue (MOCART) score. Results: There was no significant difference between groups demographically (P > .05). All patients with dp-AOT and sp-AOT showed a significant pre- to postoperative increase in FAOS and SF-12 scores (P < .001). When comparing preoperative scores for both groups, there was no statistical significance between sp-AOT and dp-AOT scores (FAOS, P = .719; SF-12, P = .947). There was no significant difference in functional scores between the 2 groups postoperatively for both FAOS (P = .883) and SF-12 (P = .246). Mean MOCART scores did not exhibit any statistically significant difference between groups (P = .475). Two patients complained of knee donor site stiffness (4.8%), which later resolved. Conclusion: Patients with large OCLs treated using a dp-AOT procedure did not show inferior clinical or radiological outcomes compared with those treated with sp-AOT at a minimum 5-year follow-up. The dp-AOT procedure is as effective as sp-AOT in treating larger OCLs of the talar dome in the intermediate term, with similar high postoperative clinical and radiological outcomes.

Platelet-Rich Plasma May Improve Osteochondral Donor Site Healing in a Rabbit Model

Purpose The purpose of this study was to assess the effect(s) of platelet-rich plasma (PRP) on osteochondral donor site healing in a rabbit model. Methods Osteochondral donor sites 3 mm in diameter and 5 mm in depth were created bilaterally on the femoral condyles of 12 New Zealand White rabbits. Knees were randomized such that one knee in each rabbit received an intra-articular injection of PRP and the other received saline (placebo). Rabbits were euthanized at 3, 6, and 12 weeks following surgery. Repair tissue was evaluated using the International Cartilage Repair Society (ICRS) macroscopic and histological scores. Results No complications occurred as a result of the interventions. There was no significant difference in macroscopic scores between the 2 groups (5.5 ± 3.8 vs. 3.8 ± 3.5; P = 0.13). Subjective macroscopic assessment determined greater tissue infill with fewer fissures and a more cartilage-like appearance in PRP-treated knees. Overall ICRS histological scores were better in the PRP group compared with the placebo (9.8 ± 2.0 vs. 7.8 ± 1.8; P = 0.04). Histological scores were also higher in the PRP group compared with the placebo group at each time point. Greater glycosaminoglycan and type II collagen content were noted in the repair tissue of the PRP group compared with the placebo group. Conclusion The results of this study indicate that PRP used as an intra-articular injection may improve osteochondral healing in a rabbit model.

Platelet-rich plasma increases transforming growth factor-beta1 expression at graft-host interface following autologous osteochondral transplantation in a rabbit model

AIM To explore the effect of platelet-rich plasma on protein expression patterns of transforming growth factor-beta1 (TGF-β1) in cartilage following autologous osteochondral transplantation (AOT) in a rabbit knee cartilage defect model. METHODS Twelve New Zealand white rabbits received bilateral AOT. In each rabbit, one knee was randomized to receive an autologous platelet rich plasma (PRP) injection and the contralateral knee received saline injection. Rabbits were euthanized at 3, 6 and 12 wk post-operatively. Articular cartilage sections were stained with TGF-β1 antibody. Histological regions of interest (ROI) (left, right and center of the autologous grafts interfaces) were evaluated using MetaMorph. Percentage of chondrocytes positive for TGF-β1 was then assessed. RESULTS Percentage of chondrocytes positive for TGF-β1 was higher in PRP treated knees for selected ROIs (left; P = 0.03, center; P = 0.05) compared to control and was also higher in the PRP group at each post-operative time point (P = 6.6 × 10(-4), 3.1 × 10(-4) and 7.3 × 10(-3) for 3, 6 and 12 wk, respectively). TGF-β1 expression was higher in chondrocytes of PRP-treated knees (36% ± 29% vs 15% ± 18%) (P = 1.8 × 10(-6)) overall for each post-operative time point and ROI. CONCLUSION Articular cartilage of rabbits treated with AOT and PRP exhibit increased TGF-β1 expression compared to those treated with AOT and saline. Our findings suggest that adjunctive PRP may increase TGF-β1 expression, which may play a role in the chondrogenic effect of PRP in vivo.

Platelet-Rich Plasma and Hyaluronic Acid Are Not Synergistic When Used as Biological Adjuncts with Autologous Osteochondral Transplantation:

Introduction Autologous osteochondral transplantation (AOT) is a treatment for osteochondral lesions with known concerns, including histological degradation of the graft and poor cartilage integration. Platelet-rich plasma (PRP) and hyaluronic acid (HA) have been described has having the potential to improve results. The aim of this study was to evaluate the effect of PRP and HA on AOT in a rabbit model. Methods Thirty-six rabbits underwent bilateral knee AOT treated with either the biological adjunct (PRP, n = 12; HA, n = 12; PRP + HA, n = 12) or saline (control). PRP and HA were administered as an intra-articular injection. The rabbits were euthanized at 3, 6, or 12 weeks postoperatively. The graft sections were assessed using the modified International Cartilage Repair Society (ICRS) scoring system. The results from the PRP alone group is from previously published data. Results The mean modified ICRS histological score for the PRP-treated group was higher than its control (P = 0.002). The mean modified ICRS histological score for the HA-treated group showed no difference compared with its control (P = 0.142). The mean modified ICRS histological score for the PRP + HA–treated group was higher than its control (P = 0.006). There was no difference between the mean modified ICRS scores of the PRP- and the PRP + HA–treated grafts (P = 0.445). Conclusion PRP may decrease graft degradation and improve chondral integration in an animal model. In this model, the addition of HA was not synergistic for the parameters assessed. Level of Evidence. Basic science, Level V. Clinical Relevance. PRP can be used as an adjunct to AOT, which may decrease graft degeneration and improve clinical outcomes. HA may not influence AOT.