Warm Saline Irrigation Protocol Decreases Cement Curing Time in Hip Arthroplasty.

Cementation in hip arthroplasty is a common and reliable technique for achieving a stable bone-component interface. However, there are significant costs to the patient, surgeon, and hospital related to the use of cement. It has been previously demonstrated that increasing ambient room temperature and femoral component temperature decreases cement curing time. A protocol utilizing warmed saline irrigation within the surgical field and a warm saline bath for the femoral component was developed. We performed a comparative cohort study to investigate if this protocol reduced time to cement curing in an in vivo setting. Ten patients were enrolled in the experimental group and 11 patients in the control group. Time to cement curing was significantly lower in the experimental group (7.5 minutes vs. 11.1 minutes, p < 0.0001). The use of a simple and inexpensive warmed saline irrigation protocol during cemented hip arthroplasty decreases time to cement curing.

Results of single-incision distal biceps tendon repair for early-career upper-extremity surgeons.

Background: The purpose of this investigation was to assess surgical outcomes after distal biceps tendon (DBT) repair for upper-extremity surgeons at the beginning of their careers, immediately following fellowship training. We aimed to determine if procedure times, complication rates, and clinical outcomes differed during the learning curve period for these early-career surgeons. Methods: All cases of DBT repairs performed by 2 fellowship-trained surgeons from the start of their careers were included. Demographic data as well as operative times, complication rates, and patient reported outcomes were retrospectively collected. A cumulative sum chart (CUSUM) analysis was performed for the learning curve for both operative times and complication rate. This analysis continuously compares performance of an outcome to a predefined target level. Results: A total of 78 DBT repairs performed by the two surgeons were included. In the CUSUM analysis of operative time for surgeon 1 and 2, both demonstrated a learning curve until case 4. In CUSUM analysis for complication rates, neither surgeon 1 nor surgeon 2 performed significantly worse than the target value and learning curve ranged from 14 to 21 cases. Mean Disabilities of Arm, Shoulder, and Hand score (QuickDASH) (10.65 ± 5.81) and the pain visual analog scale scores (1.13 ± 2.04) were comparable to previously reported literature. Conclusions: These data suggest that a learning curve between 4 and 20 cases exists with respect to operative times and complication rates for DBT repairs for fellowship-trained upper-extremity surgeons at the start of clinical practice. Early-career surgeons appear to have acceptable clinical results and complications relative to previously published series irrespective of their learning stage.

An analysis of body weight changes after shoulder arthroplasty.

BACKGROUND: To determine if there are postoperative weight changes for patients undergoing primary shoulder arthroplasty (SA). In addition, we aimed to determine if glycemic control (hemoglobin A1C levels) change postoperatively for patients undergoing SA. METHODS: All patients 18 years of age or older who had undergone primary SA over a 12-year period were analyzed. Patients were excluded if they did not have a preoperative body mass index or if they had less than 1-year follow-up. Baseline demographics were recorded for all patients and comparisons were made between the obese and nonobese groups. Clinically meaningful weight loss was defined as a ≥ 5% reduction in body weight postoperatively. RESULTS: A total of 469 patients met inclusion criteria. Of them, 65% of patients were obese, and the mean preoperative body mass index for all patients was 33. With a mean follow-up of 40 months, 70% of patients demonstrated clinically significant weight loss. Compared with patients without obesity, patients with obesity lost significantly more weight (10 vs. 6 kg) and demonstrated significantly greater postoperative body mass index reductions (4 vs. 2). Overall, 72% of patients with obesity demonstrated clinically meaningful postoperative weight loss of ≥5% body weight. Patients with obesity who lost weight also saw a decrease in their postoperative hemoglobin A1C: for every 10 pounds of weight loss, A1C decreased by 0.08 units. CONCLUSIONS: In our series, 72% of patients with obesity undergoing primary SA achieved clinically meaningful weight loss, with a mean follow-up of more than 3 years. Patients who lose weight after SA additionally demonstrate improved glycemic control. Surgeons and patients should balance the association between postoperative weight loss after SA with the potential increased risks of operative complications, particularly for severely obese patients.

Doxycycline improves cage activity, but not exercised, supraspinatus tendon and muscle in a rat model.

The objective of this study was to investigate the effects of doxycycline, a broad-spectrum MMP inhibitor, on cage activity and exercised supraspinatus tendon and muscle using a Sprague-Dawley rat model of non-injurious exercise. Because exercise may alter muscle and tendon MMP activity and matrix turnover, we hypothesized that doxycycline would abolish the beneficial adaptations found with exercise but have no effect on cage activity muscle and tendon properties. Rats were divided into acute or chronic exercise (EX) or cage activity (CA) groups, and half of the rats received doxycycline orally. Animals in acute EX groups were euthanized 24 h after a single bout of exercise (10 m/min, 1 h) on a flat treadmill. Animals in chronic EX groups walked on a flat treadmill and were euthanized at 2 or 8 week time points. Assays included supraspinatus tendon mechanics and histology and muscle fiber morphologic and type analysis. Doxycycline improved tendon mechanical properties and collagen organization in chronic cage activity groups, which was not consistently evident in exercised groups. Combined with exercise, doxycycline decreased average muscle fiber cross-sectional area. Results of this study suggest that administration of doxycycline at pharmaceutical doses induces beneficial supraspinatus tendon adaptations without negatively affecting the muscle in cage activity animals, supporting the use of doxycycline to combat degenerative processes associated with underuse; however, when combined with exercise, doxycycline does not consistently produce the same beneficial adaptations in rat supraspinatus tendons and reduces muscle fiber cross-sectional area, suggesting that doxycycline is not advantageous when combined with activity.

Rat supraspinatus tendon responds acutely and chronically to exercise.

The objective of this study was to identify acute responses and chronic adaptations of supraspinatus tendon to noninjurious exercise. We hypothesized that chronic exercise (EX) increases tendon mechanical properties, and a single exercise bout increases matrix metalloproteinase (MMP) activity acutely. Rats were divided into acute or chronic EX or cage activity groups. Animals in acute EX groups were euthanized, 3, 12, 24, 48, or 72 h upon completion of a single bout of exercise (10 m/min, 1 h) on a flat treadmill. Animals in chronic EX groups walked on a flat treadmill for 3 days or 1, 2, or 8 wk. Tendon histology, MMP activity, and mechanics were measured. A single bout of exercise trended toward reducing tendon mechanical properties, but 2 or 8 wk of chronic EX increased tendon mechanics. Cell density was not affected. Cells became rounder with chronic EX. All tendons were highly organized. MMP activity decreased after a single bout of exercise and returned to baseline by 72 h. MMP activity decreased after 8 wk of chronic EX. Decreased MMP activity may indicate an anabolic instead of catabolic response in contrast to injury. Results suggest that mild, acute decreases in MMP activity and tendon mechanics following a single exercise bout lead to enhanced tendon mechanical adaptations with repeated exercise bouts. This study defines acute and chronic changes of MMP activity, mechanical properties, and histology of the rat supraspinatus tendon in response to beneficial exercise and proposes a mechanism by which acute responses translate to chronic adaptations.NEW & NOTEWORTHY The line between beneficial exercise and overuse has not been elucidated. This study defines the acute and chronic temporal response to exercise of supraspinatus tendon in an in vivo model. We found that decreased matrix metalloproteinase activity and tendon mechanics after a single bout of exercise are followed by beneficial chronic adaptations of the tendon with repeated bouts. How the acute responses to exercise lead to chronic adaptations may distinguish beneficial exercise from overuse.

Ibuprofen Differentially Affects Supraspinatus Muscle and Tendon Adaptations to Exercise in a Rat Model.

BACKGROUND: Previous studies have shown that ibuprofen is detrimental to tissue healing after acute injury; however, the effects of ibuprofen when combined with noninjurious exercise are debated. HYPOTHESIS: Administration of ibuprofen to rats undergoing a noninjurious treadmill exercise protocol will abolish the beneficial adaptations found with exercise but will have no effect on sedentary muscle and tendon properties. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 167 male Sprague-Dawley rats were divided into exercise or cage activity (sedentary) groups and acute (a single bout of exercise followed by 24 hours of rest) and chronic (2 or 8 weeks of repeated exercise) response times. Half of the rats were administered ibuprofen to investigate the effects of this drug over time when combined with different activity levels (exercise and sedentary). Supraspinatus tendons were used for mechanical testing and histologic assessment (organization, cell shape, cellularity), and supraspinatus muscles were used for morphologic (fiber cross-sectional area, centrally nucleated fibers) and fiber type analysis. RESULTS: Chronic intake of ibuprofen did not impair supraspinatus tendon organization or mechanical adaptations (stiffness, modulus, maximum load, maximum stress, dynamic modulus, or viscoelastic properties) to exercise. Tendon mechanical properties were not diminished and in some instances increased with ibuprofen. In contrast, total supraspinatus muscle fiber cross-sectional area decreased with ibuprofen at chronic response times, and some fiber type-specific changes were detected. CONCLUSION: Chronic administration of ibuprofen does not impair supraspinatus tendon mechanical properties in a rat model of exercise but does decrease supraspinatus muscle fiber cross-sectional area. This fundamental study adds to the growing literature on the effects of ibuprofen on musculoskeletal tissues and provides a solid foundation on which future work can build. CLINICAL RELEVANCE: The study findings suggest that ibuprofen does not detrimentally affect regulation of supraspinatus tendon adaptations to exercise but does decrease muscle growth. Individuals should be advised on the risk of decreased muscle hypertrophy when consuming ibuprofen.