Michael D. Maloney

Platelet-rich plasma therapy - future or trend?

Chronic complex musculoskeletal injuries that are slow to heal pose challenges to physicians and researchers alike. Orthobiologics is a relatively newer science that involves application of naturally found materials from biological sources (for example, cell-based therapies), and offers exciting new possibilities to promote and accelerate bone and soft tissue healing. Platelet-rich plasma (PRP) is an orthobiologic that has recently gained popularity as an adjuvant treatment for musculoskeletal injuries. It is a volume of fractionated plasma from the patients own blood that contains platelet concentrate. The platelets contain alpha granules that are rich in several growth factors, such as platelet-derived growth factor, transforming growth factor-β, insulin-like growth factor, vascular endothelial growth factor and epidermal growth factor, which play key roles in tissue repair mechanisms. PRP has found application in diverse surgical fields to enhance bone and soft-tissue healing by placing supra-physiological concentrations of autologous platelets at the site of tissue damage. The relative ease of preparation, applicability in the clinical setting, favorable safety profile and possible beneficial outcome make PRP a promising therapeutic approach for future regenerative treatments. However, there is a large knowledge gap in our understanding of PRPs mechanism of action, which has raised skepticism regarding its potential efficacy and use. Thus, the aim of this review is to describe the various factors proposed to contribute to the biological activity of PRP, and the published pre-clinical and clinical evidence to support it. Additionally, we describe the current techniques and technology for PRP preparation, and review the present shortcomings of this therapy that will need to be overcome if it is to gain broad acceptance.

Pediatric tibial eminence fractures: evaluation and management.

Abstract Tibial eminence fractures result from both contact and noncontact injuries. Skeletally immature persons are especially at risk. In adults, isolated fractures of the tibial eminence are usually associated with higher‐energy mechanisms. The incidence of concomitant intra‐articular injuries with tibial eminence fracture is high; MRI is useful in evaluating this injury. Nondisplaced fractures are amenable to nonsurgical management. Displaced fractures are managed with arthroscopic reduction and fixation with either sutures or screws. Although most fractures heal successfully, residual laxity usually persists because of prefracture anterior cruciate ligament midsubstance attenuation. This does not typically manifest in subjective instability, and reconstruction of the anterior cruciate ligament is rarely required. Patient factors, surgeon experience, and fracture pattern must be carefully considered before undertaking surgical repair.

Sensitivities of Medial Meniscal Motion and Deformation to Material Properties of Articular Cartilage, Meniscus and Meniscal Attachments Using Design of Experiments Methods

This study investigated the role of the material properties assumed for articular cartilage, meniscus and meniscal attachments on the fit of a finite element model (FEM) to experimental data for meniscal motion and deformation due to an anterior tibial loading of 45 N in the anterior cruciate ligament-deficient knee. Taguchi style L18 orthogonal arrays were used to identify the most significant factors for further examination. A central composite design was then employed to develop a mathematical model for predicting the fit of the FEM to the experimental data as a function of the material properties and to identify the material property selections that optimize the fit. The cartilage was modeled as isotropic elastic material, the meniscus was modeled as transversely isotropic elastic material, and meniscal horn and the peripheral attachments were modeled as noncompressive and nonlinear in tension spring elements. The ability of the FEM to reproduce the experimentally measured meniscal motion and deformation was most strongly dependent on the initial strain of the meniscal horn attachments (epsilon(1H)), the linear modulus of the meniscal peripheral attachments (E(P)) and the ratio of meniscal moduli in the circumferential and transverse directions (E(theta)E(R)). Our study also successfully identified values for these critical material properties (epsilon(1H) = -5%, E(P) = 5.6 MPa, E(theta)E(R) = 20) to minimize the error in the FEM analysis of experimental results. This study illustrates the most important material properties for future experimental studies, and suggests that modeling work of meniscus, while retaining transverse isotropy, should also focus on the potential influence of nonlinear properties and inhomogeneity.

Flexible titanium nailing for the treatment of the unstable pediatric tibial fracture.

Tibia fractures in the skeletally immature patient can usually be treated without surgery. The purpose of this study was to assess the use of flexible titanium nails in the tibia that requires operative stabilization. Over a 5-year period, 16 unstable tibia fractures in 14 patients were treated with flexible titanium intramedullary nails. All charts and radiographs were reviewed. The average age was 10 years 4 months. There were three open fractures. All fractures healed. Closed injuries obtained union by an average of 8 weeks, open fractures by an average of 15 weeks. There were no malunions. The average follow-up was 1 year 5 months. There were no instances of growth arrest, remanipulations, or refracture. In the unstable pediatric tibia fracture, flexible titanium nails are an effective treatment to obtain and maintain alignment and stability.

Stresses and Strains in the Medial Meniscus of an ACL Deficient Knee under Anterior Loading: A Finite Element Analysis with Image-Based Experimental Validation

The menisci are believed to play a stabilizing role in the ACL-deficient knee, and are known to be at risk for degradation in the chronically unstable knee. Much of our understanding of this behavior is based on ex vivo experiments or clinical studies in which we must infer the function of the menisci from external measures of knee motion. More recently, studies using magnetic resonance (MR) imaging have provided more clear visualization of the motion and deformation of the menisci within the tibio-femoral articulation. In this study, we used such images to generate a finite element model of the medial compartment of an ACL-deficient knee to reproduce the meniscal position under anterior loads of 45, 76, and 107 N. Comparisons of the model predictions to boundaries digitized from images acquired in the loaded states demonstrated general agreement, with errors localized to the anterior and posterior regions of the meniscus, areas in which large shear stresses were present. Our model results suggest that further attention is needed to characterize material properties of the peripheral and horn attachments. Although overall translation of the meniscus was predicted well, the changes in curvature and distortion of the meniscus in the posterior region were not captured by the model, suggesting the need for refinement of meniscal tissue properties.

Injury Rate and Patterns Among CrossFit Athletes.

Background: CrossFit is a type of competitive exercise program that has gained widespread recognition. To date, there have been no studies that have formally examined injury rates among CrossFit participants or factors that may contribute to injury rates. Purpose: To establish an injury rate among CrossFit participants and to identify trends and associations between injury rates and demographic categories, gym characteristics, and athletic abilities among CrossFit participants. Study Design: Descriptive epidemiology study. Methods: A survey was conducted, based on validated epidemiologic injury surveillance methods, to identify patterns of injury among CrossFit participants. It was sent to CrossFit gyms in Rochester, New York; New York City, New York; and Philadelphia, Pennsylvania, and made available via a posting on the main CrossFit website. Participants were encouraged to distribute it further, and as such, there were responses from a wide geographical location. Inclusion criteria included participating in CrossFit training at a CrossFit gym in the United States. Data were collected from October 2012 to February 2013. Data analysis was performed using Fisher exact tests and chi-square tests. Results: A total of 486 CrossFit participants completed the survey, and 386 met the inclusion criteria. The overall injury rate was determined to be 19.4% (75/386). Males (53/231) were injured more frequently than females (21/150; P = .03). Across all exercises, injury rates were significantly different (P < .001), with shoulder (21/84), low back (12/84), and knee (11/84) being the most commonly injured overall. The shoulder was most commonly injured in gymnastic movements, and the low back was most commonly injured in power lifting movements. Most participants did not report prior injury (72/89; P < .001) or discomfort in the area (58/88; P < .001). Last, the injury rate was significantly decreased with trainer involvement (P = .028). Conclusion: The injury rate in CrossFit was approximately 20%. Males were more likely to sustain an injury than females. The involvement of trainers in coaching participants on their form and guiding them through the workout correlates with a decreased injury rate. The shoulder and lower back were the most commonly injured in gymnastic and power lifting movements, respectively. Participants reported primarily acute and fairly mild injuries.

Validation of GAITRite and PROMIS as high-throughput physical function outcome measures following ACL reconstruction

New healthcare demands for quality measures of elective procedures, such as anterior cruciate ligament (ACL) reconstructive surgery, warrant the establishment of high throughput outcomes for high volume clinics. To this end, we evaluated the PROMIS and GAITRite as physical function outcome measures to quantify early healing and post‐operative complications in 106 patients at pre‐operative and 3, 10, 20 and 52 weeks post‐ACL reconstruction with bone‐tendon‐bone autograft, and compared the results to the current IKDC validated outcome measure. The results showed that both PROMIS and GAITRite were significantly quicker to administer versus IKDC (p < 0.0001). Additional advantages were that PROMIS and GAITRite detected a significant decrease in physical function at 3 weeks post‐operative, and a significant improvement at 10 weeks post‐operative versus pre‐operative (p < 0.001), which were not detected with IKDC. GAITRite was limited by a low ceiling that could not detect improvement of physical function beyond 20 weeks, while both PROMIS and IKDC detected significant improvement out to 52 weeks post‐operative (p < 0.001). Linear regressions demonstrated a significant relationship between IKDC and PROMIS, with a combined correlation value of 0.8954 (p < 0.001) for all time points. Finally, ROC curve analysis demonstrated that PROMIS is a diagnostic test for poor outcomes.

Arthroscopic Evaluation of Radiofrequency Chondroplasty of the Knee

Background Considerable debate exists over the use of radiofrequency-based chondroplasty to treat partial-thickness chondral defects of the knee. This study used second-look arthroscopy to evaluate cartilage defects previously treated with bipolar radiofrequency—based chondroplasty. Hypothesis Partial-thickness articular cartilage lesions treated with bipolar radiofrequency—based chondroplasty will show no progressive deterioration. Study Design Case series; Level of evidence, 4. Methods One hundred ninety-three consecutive patients underwent bipolar radiofrequency—based chondroplasty over 38 months; 15 (25 defects treated with bipolar radiofrequency—based chondroplasty) underwent repeat arthroscopy for recurrent or new injuries. Time from the initial to repeat arthroscopy ranged from 0.7 to 32.7 months. At both procedures, the location, size, grade, and stability of lesions were evaluated, recorded, and photographed arthroscopically. Results At the initial procedure, 25 lesions treated using bipolar radiofrequency—based chondroplasty ranged from 9 to 625 mm2 (mean, 170.2 ± 131.2 mm2; median, 120 mm2); at second look, lesion size was 9 to 300 mm2 (mean, 107.7 ± 106.7 mm2; median, 100 mm2). At second look, 3 (12%) demonstrated unstable borders with damage in the surrounding cartilage that appeared to be progressive. Eight (32%) lesions were unchanged in size. Eight (32%) demonstrated partial filling with stable repair tissue, and 6 (24%) demonstrated complete filling with stable repair tissue. Lesions in the tibiofemoral compartments showed better response to radiofrequency chondroplasty than did those within the patellofemoral joint (P < .05). Conclusion Only 3 of 25 lesions demonstrated progression. More than 50% showed partial or complete filling of the defect. Bipolar radiofrequency chondroplasty is an effective way to treat partial-thickness cartilage lesions; however, long-term effects of this treatment on cartilage remain unknown.

Relevant Anatomic Landmarks and Measurements for Biceps Tenodesis

Background: Biceps tenodesis around the pectoralis major insertion may alter resting tension on the biceps, leading to unfavorable clinical outcomes. Hypothesis: The anatomic relationship between the musculotendinous junction (MTJ) of the biceps and the pectoralis major tendon will provide guidelines for anatomic location to perform biceps tenodesis with the goal of re-establishing biceps tension. Study Design: Descriptive laboratory study. Methods: Cadaveric dissections were performed that reflected the pectoralis major tendon and exposed the long head of the biceps tendon (LHBT). Calipers were used to measure the longitudinal width of the pectoralis major tendon at the humerus, 2 cm away from the humerus, and at its proximal expansion on the humerus. The distance from the proximal extent of the pectoralis major tendon footprint to the beginning of the MTJ of the biceps and the length of the MTJ of the biceps were recorded. The location of the distal end of the MTJ of the biceps relevant to the inferior border of the pectoralis major tendon was calculated. Results: The average longitudinal width of the pectoralis major tendon at its humeral insertion was 76.8 mm, the width 2 cm away from the humerus averaged 37.3 mm, and the proximal expansion averaged 13.3 mm. The MTJ of the biceps began an average of 32.4 mm distal from the proximal aspect of the pectoralis major footprint and extended for an average of 78.1 mm. The MTJ of the LHBT was calculated to extend 3.3 cm distal to the inferior border of the pectoralis major footprint. Conclusion: The MTJ of the biceps begins further proximal than may be appreciated intraoperatively. Knowledge of the anatomic relationships between the LHBT, its MTJ, and the pectoralis major tendon provides helpful guidelines for the biceps tenodesis site. The final resting spot of the most distal aspect of the MTJ of the LHBT after tenodesis should be approximately 3 cm distal to the inferior edge of the pectoralis major tendon footprint on the humerus.

Addition of a Suture Anchor for Coracoclavicular Fixation to a Superior Locking Plate Improves Stability of Type IIB Distal Clavicle Fractures

PURPOSE The purpose of this study was to determine the effect of coracoclavicular (CC) fixation on biomechanical stability in type IIB distal clavicle fractures fixed with plate and screws. METHODS Twelve fresh-frozen matched cadaveric specimens were used to create type IIB distal clavicle fractures. Dual-energy x-ray absorptiometry (DEXA) scans ensured similar bone quality. Group 1 (6 specimens) was stabilized with a superior precontoured distal clavicle locking plate and supplemental suture anchor CC fixation. Group 2 (6 specimens) followed the same construct without CC fixation. Each specimen was cyclically loaded in the coronal plane at 40 to 80 N for 17,500 cycles. Load-to-failure testing was performed on the specimens that did not fail cyclic loading. Outcome measures included mode of failure and the number of cycles or load required to create 10 mm of displacement in the construct. RESULTS All specimens (12 of 12) completed cyclic testing without failure and underwent load-to-failure testing. Group 1 specimens failed at a mean of 808.5 N (range, 635.4 to 952.3 N), whereas group 2 specimens failed at a mean of 401.3 N (range, 283.6 to 656.0 N) (P = .005). Group 1 specimens failed by anchor pullout without coracoid fracture (4 of 6) and distal clavicle fracture fragment fragmentation (1 of 6); one specimen did not fail at the maximal load the materials testing machine was capable of exerting (1,000 N). Group 2 specimens failed by distal clavicle fracture fragment fragmentation (3 of 6) and acromioclavicular (AC) joint displacement (1 of 6); 2 specimens did not fail at the maximal load of the materials testing machine. CONCLUSIONS During cyclic loading, type IIB distal clavicle fractures with and without CC fixation remain stable. CC fixation adds stability to type IIB distal clavicle fractures fixed with plate and screws when loaded to failure. CLINICAL RELEVANCE CC fixation for distal clavicle fractures is a useful adjunct to plate-and-screw fixation to augment stability of the fracture.