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Background: Restoring footprint anatomy, minimizing gap formation, and maximizing the strength of distal triceps tendon repairs are essential factors for a successful healing process and return to sport. Hypothesis: The novel V-shaped distal triceps tendon repair technique with unicortical button fixation closely restores footprint anatomy, provides minimal gap formation and high ultimate failure load, and minimizes iatrogenic fracture risk in acute/subacute distal triceps tendon tears. Study Design: Controlled laboratory study. Methods: Twenty-four cadaveric elbows (mean ± SD age, 66 ± 5 years) were randomly assigned to 1 of 3 repair groups: the transosseous cruciate repair technique (gold standard), the knotless suture-bridge repair technique, and the V-shaped distal triceps tendon repair technique. Anatomic measurements of the central triceps tendon footprint were obtained in all specimens with a 3-dimensional digitizer before and after the repair. Cyclic loading was performed for a total of 1500 cycles at a rate of 0.25 Hz, pulling in the direction of the triceps. Displacements were measured on the medial and lateral tendon sites with 2 differential variable reluctance transducers. Load to failure and construct failure mode were recorded. Results: The mean triceps bony insertion area was 399.05 ± 81.23 mm2. The transosseous cruciate repair technique restored 36.6% ± 16.8% of the native tendon insertion area, which was significantly different when compared with the knotless suture-bridge repair technique (85.2% ± 14.8%, P = .001) and the V-shaped distal triceps tendon repair technique (88.9% ± 14.8%, P = .002). Mean displacement showed no significant difference between the V-shaped distal triceps tendon repair technique (medial side, 0.75 ± 0.56 mm; lateral side, 0.99 ± 0.59 mm) and the knotless suture-bridge repair technique (1.61 ± 0.97 mm and 1.29 ± 0.8 mm) but significance between the V-shaped distal triceps tendon repair technique and the transosseous cruciate repair technique (4.91 ± 1.12 mm and 5.78 ± 0.9 mm, P < .001). Mean peak failure load of the V-shaped distal triceps tendon repair technique (732.1 ± 156.0 N) was significantly higher than that of the knotless suture-bridge repair technique (505.4 ± 173.9 N, P = .011) and the transosseous cruciate repair technique (281.1 ± 74.8 N, P < .001). Mechanism of failure differed among the 3 repairs, with the only olecranon fracture occurring in the knotless suture-bridge repair technique at the level of the lateral row suture anchors. Conclusion: At time zero, the V-shaped distal triceps tendon repair technique and the knotless suture-bridge repair technique both provided anatomic footprint coverage. Ultimate load to failure was highest for the V-shaped distal triceps tendon repair technique, while gap formation was different only in comparison with the transosseous cruciate repair technique. Clinical Relevance: The V-shaped distal triceps tendon repair technique provides an alternative procedure to other established repairs for acute/subacute distal triceps tendon ruptures. The reduced repair site motion of the V-shaped distal triceps tendon repair technique and the knotless suture-bridge repair technique at the time of surgery may allow a more aggressive rehabilitation program in the early postoperative period. [ABSTRACT FROM AUTHOR]

Background: Previous biomechanical studies regarding deltoid function during glenohumeral abduction have primarily used static testing protocols. Hypotheses: (1) Deltoid forces required for scapular plane abduction increase as simulated rotator cuff tears become larger, and (2) maximal abduction decreases despite increased deltoid forces. Study Design: Controlled laboratory study. Methods: Twelve fresh-frozen cadaveric shoulders with a mean age of 67 years (range, 64-74 years) were used. The supraspinatus and anterior, middle, and posterior deltoid tendons were attached to individual shoulder simulator actuators. Deltoid forces and maximum abduction were recorded for the following tear patterns: intact, isolated subscapularis (SSC), isolated supraspinatus (SSP), anterosuperior (SSP + SSC), posterosuperior (infraspinatus [ISP] + SSP), and massive (SSC + SSP + ISP). Optical triads tracked 3-dimensional motion during dynamic testing. Fluoroscopy and computed tomography were used to measure critical shoulder angle, acromial index, and superior humeral head migration with massive tears. Mean values for maximum glenohumeral abduction and deltoid forces were determined. Linear mixed-effects regression examined changes in motion and forces over time. Pearson product-moment correlation coefficients (r) among deltoid forces, critical shoulder angles, and acromial indices were calculated. Results: Shoulders with an intact cuff required 193.8 N (95% CI, 125.5 to 262.1) total deltoid force to achieve 79.8° (95% CI, 66.4° to 93.2°) of maximum glenohumeral abduction. Compared with native shoulders, abduction decreased after simulated SSP (–27.2%; 95% CI, –43.3% to –11.1%, P = .04), anterosuperior (–51.5%; 95% CI, –70.2% to –32.8%, P < .01), and massive (–48.4%; 95% CI, –65.2% to –31.5%, P < .01) cuff tears. Increased total deltoid forces were required for simulated anterosuperior (+108.1%; 95% CI, 68.7% to 147.5%, P < .01) and massive (+57.2%; 95% CI, 19.6% to 94.7%, P = .05) cuff tears. Anterior deltoid forces were significantly greater in anterosuperior (P < .01) and massive (P = .03) tears. Middle deltoid forces were greater with anterosuperior tears (P = .03). Posterior deltoid forces were greater with anterosuperior (P = .02) and posterosuperior (P = .04) tears. Anterior deltoid force was negatively correlated (r = −0.89, P = .01) with critical shoulder angle (34.3°; 95% CI, 32.0° to 36.6°). Deltoid forces had no statistical correlation with acromial index (0.55; 95% CI, 0.48 to 0.61). Superior migration was 8.3 mm (95% CI, 5.5 to 11.1 mm) during testing of massive rotator cuff tears. Conclusion: Shoulders with rotator cuff tears require considerable compensatory deltoid function to prevent abduction motion loss. Anterosuperior tears resulted in the largest motion loss despite the greatest increase in deltoid force. Clinical Relevance: Rotator cuff tears place more strain on the deltoid to prevent abduction motion loss. Fatigue or injury to the deltoid may result in a precipitous decline in abduction, regardless of tear size. [ABSTRACT FROM AUTHOR]

Background: Numerous studies have identified factors that may affect the chances of rotator cuff healing after surgery. Intraoperative tendon quality may be used to predict healing and to determine type of repair and/or consideration of augmentation. There are no data that correlate how gross tendon morphology and degree of tendinopathy affect patient outcome or postoperative tendon healing. Purpose/Hypothesis: The purposes of this study were to (1) compare the gross appearance of the tendon edge during arthroscopic rotator cuff repair with its histological degree of tendinopathy and (2) determine if gross appearance correlated with postoperative repair integrity. The hypothesis was that gross (macroscopic) tendon with normal thickness, no delamination, and elastic tissue before repair would have a correlation with low Bonar scores, higher postoperative American Shoulder and Elbow Surgeons (ASES) scores, and increased rates of postoperative tendon healing on ultrasound. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 105 patients undergoing repair of medium-size (1-3 cm) full-thickness rotator cuff tears were enrolled in the study. Intraoperatively, the supraspinatus tendon was rated on thickness, fraying, and stiffness. Tendon tissue was recovered for histological analysis based on the Bonar scoring system. Postoperative ASES and ultrasound assessment of healing were obtained 1 year after repair. Correlation between gross appearance of the tendon and rotator cuff histology was determined. Results: Of the 105 patients, 85 were followed the study to completion. The mean age of the patients was 61.6 years; Bonar score, 7.5; preoperative ASES score, 49; and postoperative ASES score, 86. Ninety-one percent of repairs were intact on ultrasound. Gross appearance of torn rotator cuff tendon tissue did not correlate with histological appearance. Neither histological (Bonar) score nor gross appearance correlated with multivariate analysis of ASES score, postoperative repair status, or demographic data. Conclusion: The degree of tendinopathy did not correlate with morphological appearance of the tendon. Neither of these parameters correlated with healing or patient outcome. This study suggests that the degree of tendinopathy, unlike muscle atrophy, may not be predictive of outcomes and that, on appearance, poor quality tendon has adequate healing capacity. Therefore, abnormal gross tendon appearance should not affect the repair effort or technique. [ABSTRACT FROM AUTHOR]

Background: The anatomic restoration of glenoid morphology with an implant-free J-shaped iliac crest bone graft offers an alternative to currently widely used glenoid reconstruction techniques. No biomechanical data on the J-bone grafting technique are currently available. Purpose: To evaluate (1) glenohumeral contact patterns, (2) graft fixation under cyclic loading, and (3) the initial stabilizing effect of anatomic glenoid reconstruction with the implant-free J-bone grafting technique. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric shoulders and J-shaped iliac crest bone grafts were used for this study. J-bone grafts were harvested, prepared, and implanted according to a previously described, clinically used technique. Glenohumeral contact patterns were measured using dynamic pressure-sensitive sensors under a compressive load of 440 N with the humerus in (a) 30° of abduction, (b) 30° of abduction and 60° of external rotation, (c) 60° of abduction, and (d) 60° of abduction and 60° of external rotation. Using a custom shoulder-testing system allowing positioning with 6 degrees of freedom, a compressive load of 50 N was applied, and the peak force needed to translate the humeral head 10 mm anteriorly at a rate of 2.0 mm/s was recorded. All tests were performed (1) for the intact glenoid, (2) after the creation of a 30% anterior osseous glenoid defect parallel to the longitudinal axis of the glenoid, and (3) after anatomic glenoid reconstruction with an implant-free J-bone graft. Furthermore, after glenoid reconstruction, each specimen was translated anteriorly for 5 mm at a rate of 4.0 mm/s for a total of 3000 cycles while logging graft protrusion and mediolateral bending motions. Graft micromovements were recorded using 2 high-resolution, linear differential variable reluctance transducer strain gauges placed in line with the long leg of the graft and the mediolateral direction, respectively. Results: The creation of a 30% glenoid defect significantly decreased glenohumeral contact areas (P < .05) but significantly increased contact pressures at all abduction and rotation positions (P < .05). Glenoid reconstruction restored the contact area and contact pressure back to levels of the native glenohumeral joint in all tested positions. The mean (±SD) force to translate the humeral head anteriorly for 10 mm (60° of abduction: 31.7 ± 12.6 N; 60° of abduction and 60° of external rotation: 28.6 ± 7.6 N) was significantly reduced after the creation of a 30% anterior bone glenoid defect (60° of abduction: 12.2 ± 6.8 N; 60° of abduction and 60° of external rotation: 11.4 ± 5.4 N; P < .001). After glenoid reconstruction with a J-bone graft, the mean peak translational force significantly increased (60° of abduction: 85.0 ± 8.2 N; 60° of abduction and 60° of external rotation: 73.6 ± 4.5 N; P < .001) compared with the defect state and baseline. The mean total graft protrusion under cyclical translation of the humeral head over 3000 cycles was 138.3 ± 169.8 μm, whereas the mean maximal mediolateral graft deflection was 320.1 ± 475.7 μm. Conclusion: Implant-free anatomic glenoid reconstruction with the J-bone grafting technique restored near-native glenohumeral contact areas and pressures, provided secure initial graft fixation, and demonstrated excellent osseous glenohumeral stability at time zero. Clinical Relevance: The implant-free J-bone graft is a viable alternative to commonly used glenoid reconstruction techniques, providing excellent graft fixation and glenohumeral stability immediately postoperatively. The normalization of glenohumeral contact patterns after reconstruction could potentially avoid the progression of dislocation arthropathy. [ABSTRACT FROM AUTHOR]

Background: Pectoralis major (PM) ruptures are increasingly common, and a variety of surgical techniques have been described. However, tested techniques have demonstrated diminished strength with inadequate restoration of the footprint and suture failure at relatively low loads. Purpose/Hypothesis: The purpose was to biomechanically compare PM transosseous suture repair (current gold standard) to modern PM repair techniques that use larger caliber sutures, suture tape, and unicortical button fixation (UBF). The null hypothesis was that there would be no mechanical difference between repair techniques and no difference in the amount of footprint restoration. Study Design: Controlled laboratory study. Methods: Twenty-four fresh-frozen cadaveric shoulders controlled for age and bone mineral density were randomized equally to 4 groups: (1) UBF, suture tape; (2) UBF, No. 5 suture, suture tape; (3) bone trough with No. 2 suture; and (4) native PM tendon group; all groups were tested to failure. The specimens were tested under cycling loads (10 N to 125 N) with a final load-to-failure test at 1 mm/s. Failure modes were classified by location and cause of rupture based on optical markers, while tendon footprint length was measured to determine amount of footprint restoration. Results: For fixation strength, the mean peak load was significantly greater in the native tendon (1816 6 706 N) versus UBF/No. 5 suture/suture tape (794 6 168 N), UBF/suture tape (502 6 201 N), and bone trough (492 6 151 N) (P \ .001 for all). UBF/No. 5 suture/suture tape featured the lowest displacement superiorly (1.09 6 0.47 mm) and inferiorly (1.14 6 0.39 mm) with a significant difference compared with bone trough. With regard to tendon footprint reapproximation, cortical button fixation best approximated native tendon footprint length versus bone trough. Conclusion: Based on peak failure load, the UBF/No. 5 suture/suture tape construct demonstrated 61% greater construct strength than a traditional bone trough technique. Moreover, displacement after cyclic loading was by far smallest in the UBF/No. 5 suture/ suture tape construct. Therefore, repair constructs with larger caliber suture and suture tape provide a measurable improvement in construct strength versus traditional PM repair techniques in a biomechanical model and may be advantageous for repair. Clinical Relevance: Cortical button fixation with larger caliber suture and suture tape allows for a significantly better PM repair than more traditional techniques at the time of surgery, which may ultimately result in improved clinical outcomes if implemented in surgical practice. [ABSTRACT FROM AUTHOR]

Background: The use of corticosteroids and local anesthetics to treat osteoarthritis has established benefits, including relief of pain and increased range of motion, but may also have the potential to lead to tissue atrophy or degeneration, specifically on chondrocytes. There is growing evidence that platelet-rich plasma (PRP) has anti-inflammatory characteristics that can limit the cytotoxic effects of corticosteroids and local anesthetics. Hypothesis/Purpose: The purpose of this study was to determine the effects of PRP in chondrocyte cultures when combined with corticosteroids or local anesthetics. The hypothesis of this study was that PRP would (1) dampen the negative effects on chondrocyte viability and (2) improve chondrocyte proliferation seen with corticosteroid or local anesthetic treatment alone. Study Design: Controlled laboratory study. Methods: Peripheral blood was obtained from 8 healthy participants, followed by centrifugation to obtain PRP. Human chondrocytes were treated with PRP alone or in combination with corticosteroids or local anesthetics. Saline (concentration of 0.9%) served as the control. Luminescence and radioactive thymidine assays were performed to examine chondrocyte viability and proliferation, respectively. Cell exposures of 0, 5, 10, and 30 minutes were used for viability and 120 hours for proliferation. Results: The presence of PRP significantly limited the negative effect on chondrocyte viability at tested time points for the examined corticosteroids and local anesthetics (P < .05). PRP in addition to corticosteroids and local anesthetics significantly improved chondrocyte proliferation (P<.05). Conclusion: The addition of PRP can significantly reduce the cytotoxic effects of corticosteroids and/or local anesthetics applied to chondrocytes. PRP can improve the proliferation of chondrocytes compared with corticosteroids or local anesthetics alone. Clinical Relevance: With the use of corticosteroids and local anesthetics for temporary symptomatic relief and improvement of function to treat the chronic progressive nature of osteoarthritis, long-term negative effects of these agents can be limited with the parallel use of PRP. [ABSTRACT FROM AUTHOR]

The article focuses on a controlled laboratory study conducted to determine the impact of intratendinous ossifications, retrocalcaneal bursitis or intratendinous necrosis in healing tendon injuries. These factors are normally associated with insertional tendinosis which results in complete detachment of Achilles tendon from bone-to-tendon junction. The results showed that for Achilles tendonitis biomechanical stability is restored after good postoperative healing.

Background: Clinical application of platelet-rich plasma (PRP) in the realm of orthopaedic sports medicine has yielded variable results. Differences in separation methods and variability of the individual may contribute to these variable results. Purpose: To compare the effects of different PRP separation methods on human bone, muscle, and tendon cells in an in vitro model. Study Design: Controlled laboratory study. Methods: Blood collected from 8 participants (mean 6 SD age 31.6 6 10.9 years) was used to obtain PRP preparations. Three different PRP separation methods were used: a single-spin process yielding a lower platelet concentration (PRPLP), a single-spin process yielding high platelet and white blood cell concentrations (PRPHP), and a double-spin that produces a higher platelet concentration and lower white blood cell concentration (PRPDS). Human bone, muscle, and tendon cells obtained from discarded tissue samples during shoulder surgery were placed into culture and treated with the 3 PRP preparations, control media (2% fetal bovine serum [FBS] and 10% FBS), and native blood. Radioactive thymidine assays were obtained to examine cell proliferation, and testing with enzyme-linked immunosorbent assay was used to determine growth factor concentrations. Results: Addition of PRPLP to osteocytes, myocytes, and tenocytes significantly increased cell proliferation (P .05) compared with the controls. Adding PRPDS to osteoblasts and tenocytes increased cell proliferation significantly (P .05), but no significance was shown for its addition to myocytes. The addition of PRPHP significantly increased cell proliferation compared with the controls only when added to tenocytes (P .05). Osteoblasts: Proliferation was significantly increased by addition of PRPLP compared with all controls (2% FBS, 10% FBS, native blood) (P .05). Addition of PRPDS led to significantly increased proliferation compared with all controls, native blood, and PRPHP (P .05). Proliferation was significantly less when PRPHP was added compared with PRPDS (P .05). Myocytes: Proliferation was significantly increased by addition of PRPLP compared with native blood (P .05). Adding PRPHP or PRPDS to myocytes showed no significant increase in proliferation compared with the controls or the other separations. Tenocytes: Proliferation was significantly increased by addition of PRPLP compared with all controls (2% FBS, 10% FBS, native blood) (P .05). Addition of PRPDS showed a significant increase compared with the controls and native blood. For tenocytes, there was a significant increase (P .05) seen when PRPHP was added compared with the controls and native blood but not compared with the other separations. Conclusion: The primary findings of this study suggest the application of different PRP separations may result in a potential beneficial effect on the clinically relevant target cells in vitro. However, it is unclear which platelet concentration or PRP preparation may be optimal for the treatment of various cell types. In addition, a ‘‘more is better’’ theory for the use of higher platelet concentrations cannot be supported. This study was not intended to prove efficacy but to provide a platform for future research to be built upon. Clinical Relevance: The utilization of different PRP separations may result in a potentially beneficial effect on the clinically relevant target cells in vitro, but it is unclear which platelet concentration or PRP preparation may be optimal for the treatment of various cell types. [ABSTRACT FROM AUTHOR]

Background: Rotator cuff reconstructions may be improved by adding growth factors, cells, or other biologic factors into the repair zone. This usually requires a biological carrier (scaffold) to be integrated into the construct and placed in the area of tendon-to-bone healing. This needs to be done without affecting the constructs mechanics.Hypothesis/Purpose: The hypothesis was that scaffold placement, as an interposition, has no adverse effects on biomechanical properties of double-row rotator cuff repair. The purpose of this study was to examine the effect of scaffold interposition on the initial strength of rotator cuff repairs.Study Design: Controlled laboratory study.Methods: Twenty-five fresh-frozen shoulders (mean age: 65.5 ± 8.9 years) were randomly assigned to 5 groups. Groups were chosen to represent a broad spectrum of commonly used scaffold types: (1) double-row repair without augmentation, (2) double-row repair with interposition of a fibrin clot (Viscogel), (3) double-row repair with interposition of a collagen scaffold (Mucograft) between tendon and bone, (4) double-row repair with interposition of human dermis patch (ArthroFlex) between tendon and bone, and (5) double-row repair with human dermis patch (ArthroFlex) placed on top of the repair. Cyclic loading to measure displacement was performed to 3000 cycles at 1 Hz with an applied 10- to 100-N load. The ultimate load to failure was determined at a rate of 31 mm/min.Results: There were no significant differences in mean displacement under cyclic loading, slope, or energy absorbed to failure between all groups (P = .128, P = .981, P = .105). Ultimate load to failure of repairs that used the collagen patch as an interposition (573.3 ± 75.6 N) and a dermis patch on top of the reconstruction (575.8 ± 22.6 N) was higher compared with the repair without a scaffold (348.9 ± 98.8 N; P = .018 and P = .025). No significant differences were found for repairs with the fibrin clot as an interposition (426.9 ± 103.6 N) and the decellularized dermis patch as an interposition (469.9 ± 148.6 N; P = .73 and P = .35).Conclusion: Scaffold augmentation did not adversely affect the zero time strength of the tested standard double-row rotator cuff repairs. An increased ultimate load to failure was observed for 2 of the augmentation methods (collagen patch as an interposition and decellularized dermis patch on top of the reconstruction) compared with the nonaugmented repairs.Clinical Relevance: Scaffolds intended for application of growth factors or cellular components in a repair situation did not adversely jeopardize the stability of the operative construct. [ABSTRACT FROM PUBLISHER]

Background: Reconstructions of the coracoclavicular (CC) ligament in an open or arthroscopically assisted procedure are often combined with a resection of the distal clavicle to prevent or treat osteoarthritic degenerations of the acromioclavicular (AC) joint. However, increased horizontal translation leading to symptomatic instability may be associated with resection of the distal clavicle.Hypothesis: Horizontal translation increases in direct correlation to subsequent resection of the distal clavicle.Study Design: Controlled laboratory study.Methods: Twelve fresh-frozen specimens (mean age, 82.0 ± 5 years) were examined using a servohydraulic testing system. A 70-N force was applied in the anterior, posterior, and superior directions, and the translations were quantified for all directions. After native testing, sequential resection of the distal clavicle at 5 and 10 mm was performed after incision of the inferior capsule, and anterior-posterior loads were retested. Finally, the AC ligaments were incised, and repeated testing was performed.Results: Native mean (± standard deviation) anterior translation was 7.90 ± 2.62 mm. After section of the inferior AC capsule, anterior translation was 8.05 ± 2.62 mm (P = 1.0). After clavicle resection of 5 mm, anterior translation was 10.75 ± 2.38 mm (P = .122), and after resection of 10 mm, anterior translation was significantly increased to 11.6 ± 2.37 mm (P = .012). Complete AC capsule sectioning led to significantly greater amounts of anterior translation (12.12 ± 3.0 mm; P = .003). Posterior translation for the native specimen was 8.88 ± 2.63 mm. Sectioning of the inferior AC capsule resulted in 9.21 ± 2.71-mm translation (P = 1.0). After clavicle resection of 5 mm, posterior translation was 10.42 ± 2.42 mm (P = 1.0), and after 10-mm resection, it was 11.31 ± 2.86 mm (P = .39). Sectioning of the complete AC capsule led to significantly greater amounts of posterior translation (12.31 ± 3.12 mm; P = .043).Conclusion: Ten millimeters of resection increased anterior translation of the distal clavicle with both the superior and posterior AC capsules as well as the CC ligaments intact. Both anterior and posterior translations increased after 10-mm resection and complete AC capsule sectioning.Clinical Relevance: These results suggest that resection of the distal clavicle leads to increased horizontal translation despite an intact superior and posterior AC capsule. Only sparing resection of the distal clavicle should be performed and only if strictly indicated. Violation of the AC capsule further increases horizontal translation and should therefore be avoided, or if indicated in AC joint dislocations, a reconstruction of the AC capsule should be considered. [ABSTRACT FROM PUBLISHER]