Bryan G. Beutel

Correlation of Obesity With Patient-Reported Outcomes and Complications After Hip Arthroscopy

PURPOSE This study aimed to evaluate patient-reported outcomes and complications after hip arthroscopy in an obese population compared with a matched nonobese control group with a minimum 2-year follow-up, using the Modified Harris Hip Score (MHHS) and Nonarthritic Hip Score (NAHS). METHODS Data were analyzed from 21 consecutive obese patients (body mass index [BMI] ≥ 30) and 18 nonobese patients (BMI < 25) who underwent hip arthroscopy between 2009 and 2012 with a minimum follow-up of 2 years. Data collected included MHHS, NAHS, traction and intraoperative times, and postoperative complications. RESULTS Traction times were similar between obese and nonobese patients at 48 and 45 minutes (P = .51), respectively. Operative times were also similar at 54 and 51 minutes (P = .79), respectively. Each group had a statistically significant improvement in MHHS from baseline to final follow-up: 45 to 79 (P < .001) in the obese group and 49 to 81 (P < .001) in the nonobese cohort. Similarly, the NAHS showed significant improvement in each group from baseline to final follow-up: 43 to 75 (P < .001) in the obese cohort and 45 to 83 (P < .001) in the nonobese group. There was no difference between groups in MHHS or NAHS data. There were 8 complications in the obese group, most commonly deep vein thrombosis (DVT) and worsened pain, whereas the nonobese cohort had one complication (an instance of heterotopic ossification [HO]). Overall, obese patients had 11.1 times the risk of a complication developing than did nonobese patients (95% confidence interval, 1.2 to 99.7). CONCLUSIONS Hip arthroscopy in the obese patient population leads to improved short- to mid-term patient-reported outcomes similar to those seen in nonobese patients. Obese patients, however, are at a significantly increased risk of postoperative complications such as DVTs and worsened hip pain. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Characterization of damage mechanisms associated with reference point indentation in human bone

Measurement of bone mineral density (BMD) is the clinical gold standard in cases of compromised skeletal integrity, such as with osteoporosis. While BMD is a useful measurement to index skeletal health, it is also limited since it cannot directly assess any mechanical properties. The ability to directly assess mechanical properties of bone tissue would be clinically important. Reference point indentation (RPI) is a technology that has been designed to try and achieve this goal. While RPI has been shown to detect altered bone tissue properties, the underlying physical mechanism of these measurements has not been characterized. Thus, we designed a study whereby the contribution of (1) test cycle number and (2) test load level to RPI test-induced sub-surface damage was characterized and quantified. Standardized specimens were prepared from cadaveric human tibiae (n=6), such that 12 replicates of each testing condition could be carried out. A custom rig was fabricated to accurately position and map indentation sites. One set of tests was carried out with 1, 5, 10, 15 and 20 cycles (Max Load: 8 N, Freq: 2 Hz), and a second set of tests was carried out with Load levels of 2, 4, 6, 8 or 10 N (Cycle number: 20, Freq: 2 Hz). The RPI parameter Loading Slope (LS) was cycle dependent at 5, 10, 15 and 20 cycles (p<0.05). First Cycle Indentation Distance (ID 1st), Total Indentation Distance (TID), Mean Energy Dissipation (ED), First Cycle Unloading Slope (US 1st), Mean Unloading Slope (US) and LS were significantly different at 6, 8 and 10 N compared to 2 N (p<0.05). From the histomorphometric measurements, damage zone span was significantly different after 5, 10, 15 and 20 cycles compared with 1 cycle while indent profile width and indent profile depth were significantly different at 10, 15 and 20 cycles (p<0.05). With the load varying protocol, each of these parameters differed significantly at each increased load level (4, 6, 8, 10 N) compared with the basal level of 2 N (p<0.05). The damage area parameter in both protocols was significantly different from baseline at the three upper levels tested (i.e. 10, 15, 20 cycles and 6, 8, 10 N, in cycle and load variant protocols, respectively). Specimens were scanned by micro-computed tomography, which showed no material or microstructural differences between samples, and processed for histological analyses and damage quantification. Consistent microdamage patterns were present with evidence of damage via compaction at the indented regions. While damage in the direction of loading was established early, the damage area then increased radially with cycle number. These data help to further understand the physical manifestations of RPI parameters and will help to further facilitate its use as a clinical diagnostic tool.

Three-dimensional analysis of elbow soft tissue footprints and anatomy

BACKGROUND Tendinous and ligamentous injuries commonly occur in the elbow. This study characterized the location, surface areas, and origin and insertional footprints of major elbow capsuloligamentous and tendinous structures in relation to bony landmarks with the use of a precision 3-dimensional modeling system. METHODS Nine unpaired cadaveric elbow specimens were dissected and mounted on a custom jig. Mapping of the medial collateral ligament (MCL), lateral ulnar collateral ligament (LUCL), triceps, biceps, brachialis, and capsular reflections was then performed with 3-dimensional digitizing technology. The location, surface areas, and footprints of the soft tissues were calculated. RESULTS The MCL had a mean origin (humeral) footprint of 216 mm(2), insertional footprint of 154 mm(2), and surface area of 421 mm(2). The LUCL had a mean origin footprint of 136 mm(2), an insertional footprint of 142 mm(2), and a surface area of 532 mm(2). Of the tendons, the triceps maintained the largest insertional footprint, followed by the brachialis and the biceps (P < .001-.03). The MCL, LUCL, and biceps footprint locations were consistent, with little variability. The surface areas of the anterior (1251 mm(2)) and posterior (1147 mm(2)) capsular reflections were similar (P = .82), and the anterior capsule extended farther proximally. CONCLUSION Restoring the normal anatomy of key elbow capsuloligamentous and tendinous structures is crucial for effective reconstruction after bony or soft tissue trauma. This study provides the upper extremity surgeon with information that may aid in restoring elbow biomechanics and preserving range of motion in these patients.

The Masters Athlete: A Review of Current Exercise and Treatment Recommendations.

Context: With the ever-increasing number of masters athletes, it is necessary to understand how to best provide medical support to this expanding population using a multidisciplinary approach. Evidence Acquisition: Relevant articles published between 2000 and 2013 using the search terms masters athlete and aging and exercise were identified using MEDLINE. Study Design: Clinical review. Level of Evidence: Level 3. Results: Preparticipation screening should assess a variety of medical comorbidities, with emphasis on cardiovascular health in high-risk patients. The masters athlete should partake in moderate aerobic exercise and also incorporate resistance and flexibility training. A basic understanding of physiology and age-related changes in muscle composition and declines in performance are prerequisites for providing appropriate care. Osteoarthritis and joint arthroplasty are not contraindications to exercise, and analgesia has an appropriate role in the setting of acute or chronic injuries. Masters athletes should follow regular training regimens to maximize their potential while minimizing their likelihood of injuries. Conclusion: Overall, masters athletes represent a unique population and should be cared for utilizing a multidisciplinary approach. This care should be implemented not only during competitions but also between events when training and injury are more likely to occur. Strength of Recommendation Taxonomy (SORT): B.

Hip arthroscopy outcomes, complications, and traction safety in patients with prior lower-extremity arthroplasty

PurposeGiven the potential for injury due to joint-distraction techniques during hip arthroscopy, this study investigated the outcomes and safety of traction during hip arthroscopy in a series of patients with a prior lower-extremity arthroplasty.MethodsNine patients with a prior hip or knee arthroplasty (Group 1) and a matched cohort of nine additional patients with no prior hip surgery (Group 2) who underwent hip arthroscopy with traction between 2011 and 2013 were evaluated. Collected data included traction and operative times, Modified Harris Hip Scores (MHHS), Non-Arthritic Hip Scores (NAHS), and postoperative complications.ResultsBoth operative (p = 1) and traction (p = 0.11) times were similar in each group. Each group had a significant improvement in MHHS from baseline to final follow-up: from 39 to 73 (p < 0.001) in Group 1 and from 49 to 75 (p = 0.03) in Group 2. Similarly, the NAHS showed significant improvement in each group from baseline to final follow-up: from 41 to 71 (p < 0.001) in Group 1 and from 48 to 74 (p = 0.02) in Group 2. There was no difference between groups in MHHS or NAHS. There was one postoperative complication in Group 1 (a recurrent labral tear) and no complications from an existing arthroplasty or in Group 2.ConclusionsHip arthroscopy in patients with a lower-extremity arthroplasty yields improved short-term clinical outcomes without increased complications. The use of traction during hip arthroscopy is safe in this population.

Implant design and its effects on osseointegration over time within cortical and trabecular bone.

Healing chambers present at the interface between implant and bone have become a target for improving osseointegration. The objective of the present study was to compare osseointegration of several implant healing chamber configurations at early time points and regions of interest within bone using an in vivo animal femur model. Six implants, each with a different healing chamber configuration, were surgically implanted into each femur of six skeletally mature beagle dogs (n = 12 implants per dog, total n = 72). The implants were harvested at 3 and 5 weeks post-implantation, non-decalcified processed to slides, and underwent histomorphometry with measurement of bone-to-implant contact (BIC) and bone area fraction occupied (BAFO) within healing chambers at both cortical and trabecular bone sites. Microscopy demonstrated predominantly woven bone at 3 weeks and initial replacement of woven bone by lamellar bone by 5 weeks. BIC and BAFO were both significantly increased by 5 weeks (p < 0.001), and significantly higher in cortical than trabecular bone (p < 0.001). The trapezoidal healing chamber design demonstrated a higher BIC than other configurations. Overall, a strong temporal and region-specific dependence of implant osseointegration in femurs was noted. Moreover, the findings suggest that a trapezoidal healing chamber configuration may facilitate the best osseointegration.

Assessment of Atmospheric Pressure Plasma Treatment for Implant Osseointegration

This study assessed the osseointegrative effects of atmospheric pressure plasma (APP) surface treatment for implants in a canine model. Control surfaces were untreated textured titanium (Ti) and calcium phosphate (CaP). Experimental surfaces were their 80-second air-based APP-treated counterparts. Physicochemical characterization was performed to assess topography, surface energy, and chemical composition. One implant from each control and experimental group (four in total) was placed in one radius of each of the seven male beagles for three weeks, and one implant from each group was placed in the contralateral radius for six weeks. After sacrifice, bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were assessed. X-ray photoelectron spectroscopy showed decreased surface levels of carbon and increased Ti and oxygen, and calcium and oxygen, posttreatment for Ti and CaP surfaces, respectively. There was a significant (P < 0.001) increase in BIC for APP-treated textured Ti surfaces at six weeks but not at three weeks or for CaP surfaces. There were no significant (P = 0.57) differences for BAFO between treated and untreated surfaces for either material at either time point. This suggests that air-based APP surface treatment may improve osseointegration of textured Ti surfaces but not CaP surfaces. Studies optimizing APP parameters and applications are warranted.

Mechanical Evaluation of Four Internal Fixation Constructs for Scaphoid Fractures.

Background: The objective of this study was to compare the mechanical performance of 4 different constructs for fixation of oblique scaphoid fractures. Methods: Twenty-eight synthetic scaphoids underwent an oblique osteotomy along the dorsal sulcus. Each was randomly assigned to fixation by 1 of 4 methods: two 1.5-mm headless compression screws, one 2.2-mm screw, one 3-mm screw, or a 1.5-mm volar variable-angle plate. After fixation, scaphoids were potted at a 45° angle and loaded at the distal pole by a hydraulically driven mechanical testing system plunger until the fixation failed. Excursion and load were measured with a differential transformer and load cell, respectively. From these data, the stiffness, load-to-failure, and maximum displacement of each construct were calculated. Results: The 2.2-mm screw demonstrated the highest stiffness and the two 1.5-mm screws had the lowest. However, there were no significant differences among the fixation methods in terms of stiffness. Both 2.2- and 3-mm screw constructs had significantly higher loads-to-failure than two 1.5-mm screws. The maximum load for the plate approached, but did not achieve, statistical significance compared with the 1.5-mm screws. There was no significant difference among constructs in displacement. Conclusions: All constructs demonstrated similar mechanical properties that may provide sufficient stability for effective clinical use. Given their significantly higher loads-to-failure, a 2.2- or 3-mm screw may be superior to two 1.5-mm screws for fixation of unstable scaphoid fractures. The volar plate did not have superior mechanical characteristics to the compression screws.

Therapeutic approaches to skeletal muscle repair and healing.

Context: Skeletal muscle is comprised of a highly organized network of cells, neurovascular structures, and connective tissue. Muscle injury is typically followed by a well-orchestrated healing response that consists of the following phases: inflammation, regeneration, and fibrosis. This review presents the mechanisms of action and evidence supporting the effectiveness of various traditional and novel therapies at each phase of the skeletal muscle healing process. Evidence Acquisition: Relevant published articles were identified using MEDLINE (1978-2013). Study Design: Clinical review. Level of Evidence: Level 3. Results: To facilitate muscle healing, surgical techniques involving direct suture repair, as well as the implantation of innovative biologic scaffolds, have been developed. Nonsteroidal anti-inflammatory drugs may be potentially supplanted by nitric oxide and curcumin in modulating the inflammatory pathway. Studies in muscle regeneration have identified stem cells, myogenic factors, and β-agonists capable of enhancing the regenerative capabilities of injured tissue. Furthermore, transforming growth factor-β1 (TGF-β1) and, more recently, myostatin and the rennin-angiotensin system have been implicated in fibrous tissue formation; several antifibrotic agents have demonstrated the ability to disrupt these systems. Conclusion: Effective repair of skeletal muscle after severe injury is unlikely to be achieved with a single intervention. For full functional recovery of muscle there is a need to control inflammation, stimulate regeneration, and limit fibrosis. Strength-of-Recommendation Taxonomy (SORT): B

Evaluation of bone response to synthetic bone grafting material treated with argon-based atmospheric pressure plasma.

Bone graft materials are utilized to stimulate healing of bone defects or enhance osseointegration of implants. In order to augment these capabilities, various surface modification techniques, including atmospheric pressure plasma (APP) surface treatment, have been developed. This in vivo study sought to assess the effect of APP surface treatment on degradation and osseointegration of Synthograft™, a beta-tricalcium phosphate (β-TCP) synthetic bone graft. The experimental (APP-treated) grafts were subjected to APP treatment with argon for a period of 60s. Physicochemical characterization was performed by environmental scanning electron microscopy, surface energy (SE), and x-ray photoelectron spectroscopy analyses both before and after APP treatment. Two APP-treated and two untreated grafts were surgically implanted into four critical-size calvarial defects in each of ten New Zealand white rabbits. The defect samples were explanted after four weeks, underwent histological analysis, and the percentages of bone, soft tissue, and remaining graft material were quantified by image thresholding. Material characterization showed no differences in particle surface morphology and that the APP-treated group presented significantly higher SE along with higher amounts of the base material chemical elements on it surface. Review of defect composition showed that APP treatment did not increase bone formation or reduce the amount of soft tissue filling the defect when compared to untreated material. Histologic cross-sections demonstrated osteoblastic cell lines, osteoid deposition, and neovascularization in both groups. Ultimately, argon-based APP treatment did not enhance the osseointegration or degradation of the β-TCP graft. Future investigations should evaluate the utility of gases other than argon to enhance osseointegration through APP treatment.