Joseph P. DeAngelis

Biomechanical Evaluation of Arthroscopic Rotator Cuff Repairs Over Time

PURPOSE The aim of this study was to assess the contact pressure, force, and area over time for 4 common arthroscopic rotator cuff repair techniques. METHODS The transosseous-equivalent, single-row, triangle double-row, and suture-chain transosseous repair techniques were used to repair a full-thickness tear of the supraspinatus in 16 cadaveric shoulders. Continuous data points were collected immediately after repair and for 160 minutes at set time intervals by use of a custom thin film pressure sensor. RESULTS Each of the 4 rotator cuff repair techniques showed decreased contact force, pressure, and area 160 minutes after the repair was performed. The transosseous-equivalent construct had the highest contact pressure and force initially and at all time points up to 160 minutes. Although the 3 double-row constructs had greater pressure and force at all time points compared with the single-row repair, only the transosseous-equivalent group showed a statistically greater pressure and force when compared with single-row repair (P < .05). CONCLUSIONS Contact pressure, force, and pressurized footprint area decrease 160 minutes after repair regardless of repair technique. The transosseous-equivalent group had the highest contact pressure and force at all time points. CLINICAL RELEVANCE The decrease in contact pressure and force after rotator cuff repair may have important implications in evaluating tendon-to-bone healing and determining the optimal rehabilitation protocol.

Anatomy of the superficial peroneal nerve in relation to fixation of tibia fractures with the less invasive stabilization system.

Objective: To examine the danger to the superficial peroneal nerve during percutaneous screw placement in the distal holes of the 13-hole proximal tibia Less Invasive Stabilization System plate in a cadaver. Design: Anatomic study. Setting: Medical school anatomy laboratory. Interventions: Fourteen adult cadaveric lower extremities were used. A 13-hole proximal tibia Less Invasive Stabilization System plate was placed as described by the manufacturer. Dissection of the superficial peroneal nerve was performed following localization of screw holes 7 through 13 using insertion sleeves, centering sleeves, and 2.0-mm Kirschner wires passed through the insertion guide. Results: The average distance from the superficial peroneal nerve to the center of holes 11, 12, and 13 was 10.0 mm (range 0–21, standard deviation 5.6), 6.8 mm (range 0–16, standard deviation 4.3), and 2.7 mm (0–11, standard deviation 3.7), respectively. In 12 of 14 legs (86%), the superficial peroneal nerve was 5.0 mm or less from the center of hole 13. The nerve was touching the guide wire at hole 11 in 1 specimen (7%), at hole 12 in 2 specimens (14%), and at hole 13 in 6 specimens (43%). In 1 specimen (7%), the guide wire pierced the superficial peroneal nerve at hole 13. Conclusion: These findings suggest that the superficial peroneal nerve is at significant risk during percutaneous screw placement in holes 11 through 13 of the 13-hole proximal tibia Less Invasive Stabilization System plate. Use of a larger incision and careful dissection down to the plate in this region may minimize the risk of damage to the nerve.

Differential Patterns of Cocaine-Induced Organ Toxicity in Murine Heart versus Liver

To determine cocaines toxicity in different organs, BALB/c mice were intraperitoneally injected daily for 15 days with either saline or cocaine: 10 mg/kg, 30 mg/kg, or 60 mg/kg. Cardiac function, hepatic pathophysiology, heart and liver apoptosis, and tumor necrosis factor (TNF-α) levels were analyzed. After administration of cocaine, cardiac function decreased. Inflammatory cell infiltration and eosinophilic contraction bands were visible in the hearts of mice treated with 60mg/kg cocaine. Moreover, histopathology demonstrated that cocaine caused hepatic necrosis. TdT-mediated dUTP nick end-labeling (TUNEL) staining and DNA ladder analysis indicated that cocaine caused apoptosis in both the heart and liver. Moreover, immunoassay showed that TNF-α levels significantly increased in the heart and liver with cocaine administration. However, our RT-PCR study showed that there was no significant difference in either the heart or liver in the levels of mRNA for TNF-α between cocaine-treated and saline control mice. The present study demonstrated that cocaine is toxic to multiple organs, and at low dose can induce hepatic damage without gross pathological injury to the heart. The results suggest that the liver is more sensitive than the heart to cocaine toxicity, and induction of apoptosis or TNF-α elevation may be a common mechanism responsible for cocaines toxicity.

Comparison of All-Inside Meniscal Repair Devices With Matched Inside-Out Suture Repair

Background: All-inside meniscal repairs are performed with increasing frequency because of the availability of newly developed devices. A comparison of their biomechanical characteristics may aid physicians in selecting a method of meniscal repair. Hypothesis: All-inside meniscal repairs will be superior to their inside-out controls in response to cyclic loading and load-to-failure testing. Study Design: Controlled laboratory study. Methods: Sixty-six bucket-handle tears in matched porcine menisci were repaired using the Ultra FasT-Fix, Meniscal Cinch, Ultrabraid No. 0, and FiberWire 2-0 sutures. Initial displacement, cyclic loading (100, 300, and 500 cycles), and load-to-failure testing were performed. The displacement, response to cyclic loading, and mode of failure were recorded. The stiffness was calculated. Results: The Meniscal Cinch demonstrated a significantly higher initial displacement than the other methods tested (P = .04). No significant difference was found among the methods in response to cyclic loading. The inside-out FiberWire repair demonstrated the highest load to failure (120.8 ± 23.5 N) and was significantly higher than both the Meniscal Cinch (64.8 ± 24.1 N, P < .001) and the Ultra FasT-Fix (88.3 ± 14.3 N, P = .002). It was not significantly higher than the inside-out Ultrabraid suture repair (98.8 ± 29.2 N). The inside-out FiberWire repair had the highest stiffness (28.7 ± 7.8 N/mm). It was significantly higher than the Meniscal Cinch (18.0 ± 8.8 N/mm, P = .01). The most common mode of failure in all methods was suture failure. Conclusion: An inside-out suture repair affords surgeons the best overall biomechanical characteristics of the devices tested (initial displacement, response to cyclic loading, and load to failure). For an all-inside repair, the Ultra FasT-Fix reproduces the characteristics of its matched inside-out suture repair more closely than the Meniscal Cinch. Clinical Relevance: Inside-out sutures and all-inside devices have similar responses to cyclic loading.

Analysis of a New All-Inside Versus Inside-Out Technique for Repairing Radial Meniscal Tears

PURPOSE The purpose of this study was to compare gap formation, strength, and stiffness of repaired radial tears of the meniscus treated using a new all-inside technique versus a traditional inside-out suture technique. METHODS Radial tears were created in 36 fresh-frozen porcine menisci. Repairs were performed using a novel all-inside suture-based meniscal repair device or an inside-out technique. The repairs were tested for cyclic loading and load to failure. The displacement, response to cyclic loading (100, 300, and 500 cycles), and mode of failure were recorded, and the constructs stiffness was calculated. RESULTS The all-inside repairs using the novel device resulted in a significantly lower displacement (gap formation) after 100, 300, and 500 cycles (P = .002, P = .001, and P = .001, respectively). The ultimate load to failure was significantly greater for the all-inside repairs (111.61 N v 95.01 N; P = .03). The all-inside repairs showed greater stiffness (14.53 N/mm v 11.19 N/mm; P = .02). The all-inside repairs failed most often by suture breakage (suture failure). The inside-out repairs failed most commonly when the suture pulled through the tissue (tissue failure) (P < .001). CONCLUSIONS For repair of radial tears of the meniscus, the vertical suture configuration created by the all-inside technique resulted in lower displacement, higher load to failure, and greater stiffness compared with the horizontal inside-out technique. CLINICAL RELEVANCE In a porcine specimen meniscus repair model, the biomechanical properties of a vertical all-inside technique were superior to that of a horizontal inside-out technique. Future studies of biomechanical and clinical outcomes in human meniscal repairs with this device are warranted to explore whether this repair method is valuable to clinical practice and patient outcomes.

Does Shoe Insole Modification Prevent Stress Fractures? A Systematic Review

Stress fractures can be debilitating in athletes and military personnel. Insoles may lower stress fracture rates by improving biomechanics, lessening fatigue, and attenuating impact. The objective of this study was to systematically review the best evidence on the use of insoles as a method of stress fracture prevention in a high-risk population. Using MEDLINE, Cochrane, Current Controlled Trials, UK National Research Register, ScienceDirect, CINAHL, and EMBASE, a review of randomized (level I) and quasi-randomized (level II) controlled trials was performed using an insole as the intervention and stress fracture incidence as the primary outcome measure. Five trials were included, and a random effects model was used to generate a summary estimate and an overall odds ratio. One study found a significant reduction in overall stress fracture incidence using a semirigid insole, while four studies found no overall reduction in military personnel. However, when the data are pooled, orthotic use was beneficial. When stratified by site, there was a reduction in femoral and tibial stress fracture incidence. Shoe insoles may reduce the overall femoral and tibial stress fracture incidence during military training. It is unclear if the use of insoles would prevent stress fractures in athletes. Additional studies are necessary to determine the efficacy of insoles in an athletic population.

Traumatic Bone Bruises in the Athlete’s Knee

Context: Mobile water within the bone marrow is a physiological phenomenon that is identifiable on magnetic resonance (MR) imaging, and signal changes can result from blood pooling, reactive hyperemia, edema, and microfracture. When these MR lesions are associated with an acute traumatic event, the findings are referred to as bone bruises and so represent a unique manifestation of injury. This review discusses bone bruises in anterior cruciate ligament (ACL) tears, patella dislocations, occult fractures, and contusions. Methods: A PubMed search of the literature from 1982 to December 2009 was conducted with the terms knee and bone bruise. Results: Bone bruises are associated with ACL tears, patella dislocations, occult fractures, and contusions. For each injury, a unique pattern of bone bruising is found on MR imaging, which results from the acute trauma. When acute trauma produces a subchondral lesion with low T1-weighted and high T2-weighted signal intensity, the resulting bony contusion is best described as a bone bruise. Conclusions: Bone marrow edema is identified using MR imaging and may result from traumatic or atraumatic causes. Bone bruises can be characterized by their pattern at presentation, by the mechanism of injury, and by their associated injuries. This type of bone edema can accompany contact and noncontact ACL ruptures as well as patella dislocations. Although increased marrow edema can be associated with an occult fracture, the long-term significance of these lesions is unclear.

Understanding the superior clear space in the adult ankle

Background: The width of the medial clear space often is used to determine the integrity of the deltoid ligament, the primary medial stabilizer of the ankle joint. The normal clinical relationship of the superior clear space to the medial clear space is not well described. This investigation sought to determine if the superior clear space constitutes an accurate point of comparison for the medial clear space and a means for assessing ligamentous stability in an adult ankle. Methods: A retrospective review of consecutive ankle radiographs for a 4-month period of time was completed using a university-based radiology database. Using a digitally calibrated ruler, the widths of the medial and superior clear spaces were measured on the mortise view. These values were compared using a Students t-test. Results: Digital radiographs of 564 consecutive ankles were reviewed retrospectively and 94 cases were without evidence of trauma, surgery, or degenerative disease. The medial and superior clear spaces were measured on the mortise view and found to be 2.7 mm (standard deviation 0.5; range 1.3 mm to 4.3 mm; 95% confidence interval 1.7 mm to 3.8 mm) and 3.6 mm (standard deviation 0.6; 2.0 to 5.3; CI 2.4 mm to 4.7 mm), respectively. The average absolute difference was 0.9 mm (standard deviation 0.5; −0.7 to 1.5; CI −0.1 mm to 1.8 mm) and in 92 of 94 ankles (98%), the superior clear space was greater than or equal to the medial clear space. Conclusions: Understanding the normal radiographic relationship of the superior and medial clear spaces may help in the diagnosis of ligamentous instability in the ankle and may obviate the need for additional diagnostic tests.

The effect of simulated scapular winging on glenohumeral joint translations.

HYPOTHESIS In this study, we aim to test whether scapular winging results in a significant change in glenohumeral translation in the initial phase of the throwing motion. METHODS Six shoulders underwent an abbreviated throwing motion (ATM) from late cocking to the end of acceleration by use of a validated robotic system. The intact specimens were tested to establish a baseline. The position of the scapula was then affected to simulate scapular winging by placing a cylindrical wedge under the inferior angle of the scapula, and the ATM was performed again. For both conditions, the average glenohumeral translations and scapular rotations were plotted over time to calculate the area under the curve, as a representative of the overall glenohumeral translations and scapular rotations observed during the ATM. RESULTS Throughout the motion, the winged scapulae showed, on average, 7.7° more upward rotation, 1.6° more internal rotation, and 5.3° more anterior tipping as compared with the baseline. The scapular position relative to the hanging arm was significantly different between the baseline and scapular winging conditions in all arm positions, except for maximal external rotation and the neutral position. Comparing the area under the curve at baseline and with scapular winging indicated that scapular winging significantly increased anterior translation of the glenohumeral joint whereas translation in the superior/inferior and medial/lateral directions did not result in a change in translation. DISCUSSION These results may suggest a more important role of abnormalities in scapular position in predisposing throwing athletes to shoulder injuries of the anterior capsulolabral structures and consecutive glenohumeral instability.

Histologic Examinations of Arthroplasty Specimens are not Cost-effective: A Retrospective Cohort Study

BackgroundMany hospitals require all operative specimens be sent to pathologists for routine examination. Although previous studies indicate this practice increases medical cost, it remains unclear whether it alters patient management and whether it is cost-effective.Questions/purposesWe therefore (1) determined the rate of discordance between clinical and histologic examinations of routine operative specimens during elective primary arthroplasties, (2) determined the cost of routine histologic screening, and (3) estimated its cost-effectiveness in terms of cost per quality-adjusted life year gained, as compared with gross examination or no examination.MethodsWe retrospectively reviewed medical records of 1247 patients who underwent 1363 routine elective primary total joint arthroplasties between January 18, 2006 and March 15, 2010. We compared preoperative, postoperative, and histologic diagnoses for each patient and categorized them into three classes: concordant (clinical and histologic diagnoses agreed), discrepant (diagnoses differed but with no resultant change in treatment), and discordant (diagnoses differed with resultant change in treatment). Medicare reimbursements were determined through the pathology department’s administrative office.ResultsIn 1363 cases, 1335 (97.9%) clinical and histologic diagnoses were concordant, 28 (2.1%) were discrepant, and none were discordant. Total reimbursement for routine pathological examination was