Alignment in Total Knee Arthroplasty: Avoid Crossing Over From Varus to Valgus.

BACKGROUND: Ideal target limb alignment remains a debated topic in total knee arthroplasty (TKA). We aimed to determine the effect of limb alignment correction on patient-reported outcomes and knee range of motion (ROM) following TKA. METHODS: In this retrospective analysis, patients (N = 409) undergoing primary TKA at a single institution were studied. Using full leg-length radiographs, limb alignment was measured preoperatively and postoperatively. Patients were categorized by preoperative (Preop) alignment (varus > 0°; valgus < 0°). Preop varus patients were then divided as follows based on postoperative alignment: neutral (VAR-NEUT, 0°± 2), remaining in varus (VAR-rVAR, ≥3°), and cross-over to valgus (VAR-CO, ≤-3°). Similarly, Preop valgus patients were divided as follows for postoperative alignment: neutral (VAL-NEUT, 0°± 2), remaining in valgus (VAL-rVAL, ≤-3°), and cross-over to varus (VAL-CO, ≥3°). The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement survey scores were collected at preoperatively as well as at 6 weeks, 3, 6, and 12 months postoperatively. Knee ROM was collected at 2 weeks, 6 to 12 weeks, and >6 months postoperatively. An analysis of variance repeated on time followed by a Bonferroni post hoc test was used to compare outcomes for the postoperative alignment subgroups. RESULTS: Preop Varus patients: Those in the VAR-CO group (overcorrected to -4.03° ± 1.95valgus) were observed to have lower Knee Injury and Osteoarthritis Outcome Score for Joint Replacement scores at 3, 6, and 12 months postoperatively compared to those in the NEUT group (P < .05). This finding was paired with reduced ROM at 6 to 12 weeks postoperatively in the VAR-CO group compared to VAR-NEUT and VAR-rVAR (P < .05). Preop Valgus patients: Those in the VAL-rVal group (left in -4.39° ± 1.39valgus) were observed to have reduced knee flexion at 6 to 12 weeks postoperatively compared to VAL-NEUT and VAL-CO. CONCLUSIONS: These findings indicate that postoperative valgus alignment via either crossing over to valgus (VAR-CO) or remaining in valgus (VAL-rVAL) alignment may result in less preferable outcomes than correction to neutral or slightly varus alignment.

Postabsorptive muscle protein synthesis is higher in outpatients as compared to inpatients.

Several factors affect muscle protein synthesis (MPS) in the postabsorptive state. Extreme physical inactivity (e.g., bedrest) may reduce basal MPS, whereas walking may augment basal MPS. We hypothesized that outpatients would have a higher postabsorptive MPS than inpatients. To test this hypothesis, we conducted a retrospective analysis. We compared 152 outpatient participants who arrived at the research site the morning of the MPS assessment with 350 Inpatient participants who had an overnight stay in the hospital unit before the MPS assessment the following morning. We used stable isotopic methods and collected vastus lateralis biopsies ∼2 to 3 h apart to assess mixed MPS. MPS was ∼12% higher (P < 0.05) for outpatients than inpatients. Within a subset of participants, we discovered that after instruction to limit activity, outpatients (n = 13) took 800 to 900 steps in the morning to arrive at the unit, seven times more steps than inpatients (n = 12). We concluded that an overnight stay in the hospital as an inpatient is characterized by reduced morning activity and causes a slight but significant reduction in MPS compared with participants studied as outpatients. Researchers should be aware of physical activity status when designing and interpreting MPS results.NEW & NOTEWORTHY The postabsorptive muscle protein synthesis rate is lower in the morning after an overnight inpatient hospital stay compared with an outpatient visit. Although only a minimal amount of steps was conducted by outpatients (∼900), this was enough to increase postabsorptive muscle protein synthesis rate.

Rotator cuff training with upper extremity blood flow restriction produces favorable adaptations in division IA collegiate pitchers: a randomized trial.

BACKGROUND: Recent evidence indicates that combined upper extremity blood flow restriction (BFR, applied distally to the shoulder) and low-load resistance exercise (LIX) augments clinically meaningful responses in shoulder region tissues proximal to the occlusion site. The purpose of this investigation was to determine the efficacy of BFR-LIX for the shoulder when added to standard offseason training in Division IA collegiate baseball pitchers. We hypothesized that BFR-LIX would augment training-induced increases in shoulder-region lean mass, rotator cuff strength, and endurance. As secondary outcomes, we sought to explore the impact of BFR-LIX rotator cuff training on pitching mechanics. METHODS: Twenty-eight collegiate baseball pitchers were randomized into 2 groups (BFRN = 15 and non-BFR [NOBFR]N = 13) that, in conjunction with offseason training, performed 8 weeks of shoulder LIX (Throwing arm only; 2/week, 4 sets [30/15/15/fatigue], 20% isometric max) using 4 exercises (cable external and internal rotation [ER/IR], dumbbell scaption, and side-lying dumbbell ER). The BFR group also trained with an automated tourniquet on the proximal arm (50% occlusion). Regional lean mass (dual-energy x-ray absorptiometry), rotator cuff strength (dynamometry: IR 0 & 90, ° ER 0 & 90, ° Scaption, Flexion), and fastball biomechanics were assessed pre and post-training. Achievable workload (sets × reps × resistance) was also recorded. An ANCOVA (covaried on baseline measures) repeated on training timepoint was used to detect within-group and between-group differences in outcome measures (α = 0.05). For significant pairwise comparisons, effect size (ES) was calculated using a Cohen's d statistic and interpreted as: 0-0.1, negligible; 0.1-0.3, small; 0.3-0.5, moderate; 0.5-0.7, large; >0.7, and very large (VL). RESULTS: Following training, the BFR group experienced greater increases in shoulder-region lean mass (BFR: ↑ 227 ± 60g, NOBFR: ↑ 75 ± 37g, P = .018, ES = 1.0 VL) and isometric strength for IR 90 ° (↑ 2.4 ± 2.3 kg, P = .041, ES = 0.9VL). The NOBFR group experienced decreased shoulder flexion ↓ 1.6 ± 0.8 kg, P = .007, ES = 1.4VL) and IR at 0 ° ↓ 2.9 ± 1.5 kg, P = .004, ES = 1.1VL). The BFR group had a greater increase in achievable workload for the scaption exercise (BFR: ↑ 190 ± 3.2 kg, NOBFR: ↑ 90 ± 3.3 kg, P = .005, ES = 0.8VL). Only the NOBFR group was observed to experience changes in pitching mechanics following training with increased shoulder external rotation at lead foot contact (↑ 9.0° ± 7.9, P = .028, ES = 0.8VL) as well as reduced forward ↓ 3.6° ± 2.1, P = .001, ES = 1.2VL) and lateral ↓ 4.6° ± 3.4, P = .007, ES = 1.0VL) trunk tilt at ball release. CONCLUSION: BFR-LIX rotator cuff training performed in conjunction with a collegiate offseason program augments increases in shoulder lean mass as well as muscular endurance while maintaining rotator cuff strength and possibly pitching mechanics in a manner that may contribute to favorable outcomes and injury prevention in baseball pitching athletes.

Clinical Outcomes for Open Hip Abductor Repair Using Tenodesis and Bone Trough Repair Techniques.

BACKGROUND: Hip abductor complex tears remain an injury without a clear consensus on management. Surgical treatment has been recommended after unsuccessful nonoperative management. This study evaluates both tenodesis and bone trough techniques, with treatment choices guided by previously described tear classification. METHODS: This is a retrospective cohort study of 45 hips in 44 patients who underwent surgical treatment for symptomatic, chronic hip abductor tear unresponsive to nonoperative treatment. Demographics and preoperative and postoperative values (including visual analog scale pain scores, gait assessment, and muscle strength) were evaluated. Type I tears were treated using tendon tenodesis. Type II tears were treated through a bone trough repair. RESULTS: Forty-five hips (44 patients) were operated on with a minimum of 6-month follow-up. There were 27 type I and 18 type II tears. Eighty-seven percent of patients were female. Twenty-eight percent of type II patients (5/18) had a preexisting arthroplasty in place. Significant improvements in pain (P < .001), gait (P < .001), and muscle strength (P < .001) were achieved in both the tear types. Type I repairs showed superior results to type II repairs. However, both showed significant improvements. Postoperative magnetic resonance imaging at 6 months showed healed tenodesis in 81% (17/21) of type I tears and 50% (5/10) of type II tears. CONCLUSION: Our study shows improvement in pain and function after surgical repair of hip abductor tendon injuries in both simple and complex tears. This improvement is seen even during ongoing surgical site healing. Magnetic resonance imaging findings may remain abnormal for more than 1 year after surgery and do not clearly denote repair failure.

Intraosseous Morphine Decreases Postoperative Pain and Pain Medication Use in Total Knee Arthroplasty: A Double-Blind, Randomized Controlled Trial.

BACKGROUND: Intraosseous (IO) infusion of medication is a novel technique for total knee arthroplasty (TKA) antibiotic prophylaxis. To decrease postoperative pain in TKA patients, we investigated addition of morphine to a standard IO antibiotic injection. METHODS: A double-blind, randomized controlled trial was performed on 48 (24 each) consecutive patients undergoing primary TKA. The control group received an IO injection of antibiotics as per the standard protocol. The experimental group received an IO antibiotic injection with 10 mg of morphine. Pain, nausea, and opioid use were assessed up to 14 days postoperatively. Morphine and interleukin-6 serum levels were obtained 10 hours postoperatively in a subgroup of 20 patients. RESULTS: The experimental group had lower Visual Analog Scale pain score at 1, 2, 3, and 5 hours postoperatively (P = .0032, P = .005, P = .020, P = .010). This trend continued for postoperative day 1, 2, 8, and 9 (40% reduction, P = .001; 49% reduction, P = .036; 38% reduction, P = .025; 33% reduction, P = .041). The experimental group had lower opioid consumption than the control group for the first 48 hours and second week postsurgery (P < .05). Knee Injury and Osteoarthritis Outcome Score for Joint Replacement scores for the experimental group showed significant improvement at 2 and 8 weeks postsurgery (P < .05). Serum morphine levels in the experimental group were significantly less than the control group 10 hours after IO injection (P = .049). CONCLUSION: IO morphine combined with a standard antibiotic solution demonstrates superior postoperative pain relief immediately and up to 2 weeks. IO morphine is a safe and effective method to lessen postoperative pain in TKA patients. LEVEL OF EVIDENCE: Therapeutic, Level 1.

Impact of Valgus vs Varus Mechanical Axis Correction During Primary Total Knee Arthroplasty on Postoperative Periarticular Bone Mineral Density.

BACKGROUND: Knee periarticular bone mineral density (BMD) is influenced by limb malalignment. The purpose of this study is to determine if the nature and magnitude of alignment correction (ΔAlign°) performed during primary total knee arthroplasty (TKA) had an impact on BMD at the metaphysis of the distal femur (DFmr) and proximal tibia (PTb). METHODS: Seventy-one patients (male = 37 |female = 34; age: 65 ± 2 years) underwent full-length standing X-rays and knee-specific BMD measurements using dual-energy X-ray absorptiometry before and 3 and 6 months following TKA. A t-test was used to compare baseline demographics and knee-specific BMD measures (medial/lateral DFmr/PTb) between patients with preoperative valgus (VAL, N = 18) and varus (VAR, N = 53) malalignment. Pearson correlation analysis was used to determine if ΔAlign° correlated with site-specific knee BMD changes. A 2 (varus/valgus) by 3 (time) analysis of variance was used to compare site-specific BMD (%ΔBMD) changes following TKA. Type I error was set at α = 0.05 for all analyses. RESULTS: VAR patients had higher preoperative BMD for medial measurement at both the DFmr (VAR: 1.17 ± 0.06 g/cm2; VAL: 1.00 ± 0.09 g/cm2) and PTb (VAR: 1.41 ± 0.07 g/cm2; VAL: 1.29 ± 0.14 g/cm2) (P < .05). ΔAlign° and %ΔBMD were correlated on the medial side of the DFmr (r = 0.393, P < .05) and lateral/medial BMD ratio at the PTb (r = -0.670, P < .01) in VAL patients. Only VAL patients had significant %ΔBMD changes at 6 months postoperative with increases on the medial side only for the DFmr and PTb (+4%-8%, P < .05). CONCLUSION: Valgus patients exhibited reduced medial BMD at DFmr and PTb and showed sustained improvements 6 months postsurgery. Mechanical axis correction may be clinically impactful to bone remodeling when correcting valgus malalignment. LEVEL OF EVIDENCE: Level II, prospective cohort study.

Sex-Related Hip Strength Measures Among Professional Soccer Players.

ABSTRACT: Hedt, CA, Pearson, JM, Lambert, BS, McCulloch, PC, and Harris, JD. Sex-related hip strength measures among professional soccer players. J Strength Cond Res 35(7): 1992-1999, 2021-Lower-extremity musculoskeletal injuries in soccer are common among sexes. However, it remains unknown whether differences between sexes exist with regard to absolute or relative hip strength and how these differences may relate to injury. In the current study, we performed a retrospective cross-sectional analysis of pre-season data from male (♂n = 21) and female (♀n = 19) professional United States soccer organizations. Two years of pre-season data were collected for peak strength of lower extremity and hip musculature (no duplicates used). A 2 × 2 multivariate analysis of variance was used to detect differences in hip strength between sexes and dominant compared with nondominant legs. For all significant multivariate effects indicated by Wilks lambda and follow-up univariate analysis, a Tukey's post hoc test was used for pairwise univariate comparisons. A 2-tailed independent-samples T-test was used for comparison of height, body mass, body mass index (BMI), mean leg length, and strength ratios between dominant and nondominant limbs between sexes. Type I error was set at α = 0.05 for all analyses. Height (♂183.1 ± 6.8 cm, ♀170.0 ± 5.5 cm), body mass (♂79.0 ± 8.7 kg, ♀65.1 ± 5.6 kg), BMI (♂23.5 ± 1.3 kg·m-2, ♀22.5 ± 1.4 kg·m-2), and mean leg length (♂95.5 ± 4.34 cm, ♀ 88.3 ± 3.24 cm) differed between groups (p < 0.05). Sex differences (p < 0.05) were also found for hip abduction (dominant ♂19.5 ± 3.6 kg, ♀17.3 ± 2.2 kg; nondominant ♂18.5 ± 3.7 kg, ♀16.0 ± 2.3 kg), adduction (dominant ♂19.8 ± 3.0 kg, ♀16.7 ± 2.3 kg; nondominant ♂20.1 ± 2.9 kg, ♀17.6 ± 2.9 kg), external rotation (dominant ♂21.7 ± 3.4 kg, ♀17.7 ± 2.4 kg; nondominant ♂21.6 ± 3.9 kg, ♀16.8 ± 2.1 kg), and dominant hamstring strength (♂27.9 ± 6.5 kg, ♀23.0 ± 4.9 kg). The ratio of hip internal to external rotation strength differed in the nondominant leg (♂1.1 ± 0.2, ♀0.9 ± 0.2, p < 0.05). No significant differences were found between males and females when measures were normalized to body mass. These findings provide baseline pre-season normative data for professional soccer athletes and indicate that strength differences can be expected among different sexes, but are attenuated with attention to body mass. Further research should indicate how pre-season strength measures relate to injury.

Electromyographic Profile of the Shoulder During Stability Exercises With Kettlebells.

CONTEXT: Shoulder rehabilitation can be a difficult task due to the dynamic nature of the joint complex. Various weight training implements, including kettlebells (KB), have been utilized for therapeutic exercise in the rehabilitation setting to improve shoulder girdle strength and motor control. The KBs are unique in that they provide an unstable load and have been purported to promote greater muscle activation versus standard dumbbells. Recent literature has examined the efficacy of KB exercises for global strengthening and aerobic capacity; however, electromyographic data for shoulder-specific activities are lacking. OBJECTIVE: To examine muscle activation patterns about the rotator cuff and scapular musculature during 5 commonly-utilized KB exercises. DESIGN: Cross-sectional analysis of a single group. SETTING: Clinical biomechanics laboratory. PARTICIPANTS: Ten participants performed all exercises in a randomized order. MAIN OUTCOME MEASURES: Mean electromyographic values for each subject were compared between exercises for each target muscle. RESULTS: Significant differences (P < .05) between exercises were observed for all target muscles except for the infraspinatus. CONCLUSIONS: The data in this study indicates that certain KB exercises may elicit activation of the shoulder girdle at different capacities. Physical therapy practitioners, athletic trainers, and other clinical professionals who intend to optimize localized strengthening responses may elect to prescribe certain exercises over others due to the inherent difference in muscular utilization. Ultimately, this data may serve to guide or prioritize exercise selection to achieve higher levels of efficacy for shoulder strength and stability gains.

The Impact of Suture Caliber and Looped Configurations on the Suture-Tendon Interface in Zone II Flexor Tendon Repair.

PURPOSE: To evaluate the impact of suture caliber and looped configurations on the integrity of 4-strand modified Kessler zone II flexor tendon repairs during progressive cyclic loading. METHODS: Seventy-two flexor digitorum profundus tendons from 18 fresh human cadaver hands were divided into 4 repair groups. Thirty-six matched tendons underwent repair using either a 4-0 looped or 4-0 single-stranded suture, and an additional 36 tendons underwent 3-0 looped or 3-0 single-stranded repairs. Repair strength was tested by progressive cyclic loading. The force generating 2-mm gap formation, ultimate failure, and the mechanism of failure were recorded for each test. The impact of looped versus single-stranded configurations and the effect of tendon cross-sectional area on repair integrity were analyzed for each suture caliber. RESULTS: There was no statistically significant difference between groups regarding the force to 2-mm gap formation or ultimate failure, and all values exceeded the minimum threshold of 27 N required to withstand an early active range of motion rehabilitation protocol. The use of a 3-0 caliber suture resulted in a significantly higher proportion of repairs failing by suture pullout through the tendon substance, including 63.5% of looped and 38.9% of single-stranded core sutures. By comparison, this occurred in 11.1% of 4-0 looped and 0% of 4-0 single-stranded sutures. Larger tendon cross-sectional areas were associated with more robust repairs, particularly in the 3-0 looped group. CONCLUSIONS: In a human cadaver flexor tendon repair model, there was no significant difference in the mean force to failure between all 4 flexor tendon repair constructs under progressive cyclic loading. However, the 3-0 caliber suture failed more frequently by suture pullout, particularly with the use of a looped suture. CLINICAL RELEVANCE: Four-strand flexor tendon repairs using a 3-0 caliber suture are more prone to early failure by suture pullout under progressive cyclic loading compared with a 4-0 caliber suture.

Predicting V[Combining Dot Above]O2max From Treadmill Performance in American-Style Football Athletes.

Crouse, SF, Tolson, H, Lytle, J, Johnson, KA, Martin, SE, Green, JS, Oliver, J, Carbuhn, A, Lambert, B, and Bramhall, JP. Predicting V[Combining Dot Above]O2max from treadmill performance in American-style football athletes. J Strength Cond Res 33(4): 1028-1034, 2019-Prediction equations are often used to estimate V[Combining Dot Above]O2max in the general population but are lacking for American-style football (ASF) athletes. We sought to develop a regression model to estimate V[Combining Dot Above]O2max from treadmill exercise time in ASF athletes and compare our football V[Combining Dot Above]O2max model with 2 published prediction equations (Foster et al., 1984, and Bruce, 1973). American-style football athletes (N = 472, age = 18 ± 1 year, height = 186.1 ± 8.2 cm, and body mass = 101.8 ± 20.4 kg) underwent treadmill exercise to voluntary exhaustion (Bruce protocol). Maximal exercise time was recorded in minutes (Tmin), and V[Combining Dot Above]O2max was simultaneously measured (M-V[Combining Dot Above]O2max, mlO2·kg·min) by an automated gas-analysis system. Athletes were then randomly divided into validation and cross-validation groups (n = 236). Linear regression yielded estimates of V[Combining Dot Above]O2max from Tmin as follows: validation V[Combining Dot Above]O2max = 4.012 × Tmin - 4.628 (r = 0.678, p < 0.001, and SEE = 4.07); cross-validation V[Combining Dot Above]O2max = 4.025 × Tmin - 4.693 (r = 0.661, p < 0.001, and SEE = -4.16). These equations had a cross-validation coefficient of 0.813 and a double cross-validation coefficient of 0.823. Differences between the slopes of the 2 equations were not significant (t-test, p = 0.9603). Because validation and cross-validation groups were not statistically different on any variables measured (multivariate analysis of variance, p > 0.05), all athletes were combined to yield our final prediction equation: football V[Combining Dot Above]O2max = 4.017 × Tmin - 4.644 (r = 0.670, p < 0.001, and SEE = 4.11). Repeated-measures analysis of variance demonstrated significant differences (p < 0.001) in estimates of V[Combining Dot Above]O2max among Foster (44.1 ± 6.1), Bruce (47.1 ± 5.5), and our football (45.1 ± 5.8) equations. Foster and Bruce V[Combining Dot Above]O2max estimates were also significantly different from M-V[Combining Dot Above]O2max ((Equation is included in full-text article.)diff = -0.975 and 1.995, respectively, p < 0.001). V[Combining Dot Above]O2max of ASF athletes can be reasonably estimated by our football prediction equation using maximal treadmill time as the predictor.

The Utilization of Interval Throwing Programs in the Physical Therapy Setting: A Cross-Sectional Survey.

Context: Interval throwing programs (ITPs) have long been used in the physical therapy setting to aid in the safe and efficacious return to sport for an overhead athlete. However, the overall utilization and variation of ITPs are unknown in the physical therapy setting leading to potential inconsistencies in treatment paradigms. Objective: To determine if differences in practice patterns exist among active physical therapists of various experience levels with regard to years of experience and advanced certifications. Design: Cross-sectional survey study. Participants: A total of 133 licensed physical therapists consented to participate in an online-based survey. Experience groups were delineated based on years of practice (0-1, 1-5, 6-15, and 15+) and possession of advanced certification. Main Outcome Measures: For ranking-based data, a generalized linear mixed model was repeated across criteria response with a Bonferroni post hoc adjustment for pairwise comparisons made within and between groups (α < .05). For degree-based questions, chi-square analysis was used to compare response frequencies for options provided within each question. Results: A 76.7% response rate was achieved with 102 out of the 133 consenting individuals completed the survey. Significant differences (P < .05) were found with responses to both ranking-based and degree-based questions. However, across all groups, physical therapists agreed that throwing mechanics and customized ITP implementation were important for a successful return to throwing. Conclusions: There are inherent differences in ITP prescription among physical therapists with dissimilar experience levels. The possession of advanced certifications and years of practice seem to play a role in how interval programs are prescribed to overhead-throwing athletes. This study helps to identify differences in current physical therapy approaches toward the later stages of rehabilitation for throwing athletes. Further research should identify areas of improvement in physical therapist education as well as appropriate ITP prescription parameters to optimize care and treatment for this patient population.

Soy-Dairy Protein Blend or Whey Protein Isolate Ingestion Induces Similar Postexercise Muscle Mechanistic Target of Rapamycin Complex 1 Signaling and Protein Synthesis Responses in Older Men.

BACKGROUND: Previous work demonstrated that a soy-dairy protein blend (PB) prolongs hyperaminoacidemia and muscle protein synthesis in young adults after resistance exercise. OBJECTIVE: We investigated the effect of PB in older adults. We hypothesized that PB would prolong hyperaminoacidemia, enhancing mechanistic target of rapamycin complex 1 (mTORC1) signaling and muscle protein anabolism compared with a whey protein isolate (WPI). METHODS: This double-blind, randomized controlled trial studied men 55-75 y of age. Subjects consumed 30 g protein from WPI or PB (25% soy, 25% whey, and 50% casein) 1 h after leg extension exercise (8 sets of 10 repetitions at 70% one-repetition maximum). Blood and muscle amino acid concentrations and basal and postexercise muscle protein turnover were measured by using stable isotopic methods. Muscle mTORC1 signaling was assessed by immunoblotting. RESULTS: Both groups increased amino acid concentrations (P < 0.05) and mTORC1 signaling after protein ingestion (P < 0.05). Postexercise fractional synthesis rate (FSR; P ≥ 0.05), fractional breakdown rate (FBR; P ≥ 0.05), and net balance (P = 0.08) did not differ between groups. WPI increased FSR by 67% (mean ± SEM: rest: 0.05% ± 0.01%; postexercise: 0.09% ± 0.01%; P < 0.05), decreased FBR by 46% (rest: 0.17% ± 0.01%; postexercise: 0.09% ± 0.03%; P < 0.05), and made net balance less negative (P < 0.05). PB ingestion did not increase FSR (rest: 0.07% ± 0.03%; postexercise: 0.09% ± 0.01%; P ≥ 0.05), tended to decrease FBR by 42% (rest: 0.25% ± 0.08%; postexercise: 0.15% ± 0.08%; P = 0.08), and made net balance less negative (P < 0.05). Within-group percentage of change differences were not different between groups for FSR, FBR, or net balance (P ≥ 0.05). CONCLUSIONS: WPI and PB ingestion after exercise in older men induced similar responses in hyperaminoacidemia, mTORC1 signaling, muscle protein synthesis, and breakdown. These data add new evidence for the use of whey or soy-dairy PBs as targeted nutritional interventions to counteract sarcopenia. This trial was registered at clinicaltrials.gov as NCT01847261.

Health Status of Total Hip Versus Total Knee Arthroplasty Patients and Possible Effects on Decisions Regarding Surgical Location, Cost, and Access to Care.

Background: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are no longer considered inpatient-only procedures. Qualifying for inpatient status reimbursement requires additional, unreimbursed administrative effort, and may limit care to these patients. Purpose: We sought to evaluate and compare the overall health status of patients receiving THA and TKA. Methods: We conducted a retrospective review evaluating 2207 patients undergoing primary THA and TKA from 2015 to 2018 at a single institution. Clinical parameters, surgical procedure, medical history, laboratory values, length of stay (LOS), and discharge location were recorded and compared between the 2 groups. Results: In 2202 patients, we observed differences for body mass index (THA = 29.4 ± 0.4, TKA = 32.1 ± 0.3), low-density lipoprotein cholesterol levels (THA = 105.8 ± 13.5 mg/dL; TKA = 128.6 ± 13.7 mg/dL), and blood glucose levels (THA = 98.2 ± 1.7 mg/dL; TKA = 101.4 ± 1.3 mg/dL), indicating that TKA patients were more likely than THA patients to be classified as obese, hypercholesterolemic, and hyperglycemic. We observed longer LOS in THA patients (51.25 hours, 95% CI ± 3.87 hours) than in TKA patients (36.93 hours, 95% CI ± 1.17 hours). A greater proportion of TKA patients were discharged home (81.97%, N = 1155) rather than to additional care facilities compared with THA patients (71.84%, N = 539). Conclusion: In this retrospective study, we observed that TKA patients had higher rates of comorbidities than did THA patients, but TKA patients spent less time in the hospital and were more likely to be discharged home. Future studies should evaluate reasons for poor clinical outcomes for patients undergoing total joint arthroplasty with an outpatient designation.

Post-operative protein supplementation following orthopaedic surgery: A systematic review.

Decreased mechanical loading after orthopaedic surgery predisposes patients to develop muscle atrophy. The purpose of this review was to assess whether the evidence supports oral protein supplementation can help decrease postoperative muscle atrophy and/or improve patient outcomes following orthopaedic surgery. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). PubMed (MEDLINE), Embase, Scopus, and Web of Science were searched for randomized controlled trials that assessed protein or amino acid supplementation in patients undergoing orthopaedic surgery. Two investigators independently conducted the search using relevant Boolean operations. Primary outcomes included functional or physiologic measures of muscle atrophy or strength. Fourteen studies including 611 patients (224 males, 387 females) were analyzed. Three studies evaluated protein supplementation after ACL reconstruction (ACLR), 3 after total hip arthroplasty (THA), 5 after total knee arthroplasty (TKA), and 3 after surgical treatment of hip fracture. Protein supplementation showed beneficial effects across all types of surgery. The primary benefit was a decrease in muscle atrophy compared to placebo as measured by muscle cross sectional area. Multiple authors also demonstrated improved functional measures and quicker achievement of rehabilitation benchmarks. Protein supplementation has beneficial effects on mitigating muscle atrophy in the postoperative period following ACLR, THA, TKA, and surgical treatment of hip fracture. These effects often correlate with improved functional measures and quicker achievement of rehabilitation benchmarks. Further research is needed to evaluate long-term effects of protein supplementation and to establish standardized population-specific regimens that maximize treatment efficacy in the postoperative period.

Patient Perceptions of Same-Day Discharge Versus Overnight Stay After Total Joint Arthroplasty: Results of a Survey.

Background: In the COVID-19 era, there has been increasing interest in same-day discharge (SDD) after total joint arthroplasty (TJA). However, patient perception of SDD is not well reported. Purpose: We sought to understand patients' perceptions and preferences of postoperative care by surveying patients who have completed both an overnight stay (ONS) and an SDD after TJA. Methods: We emailed survey links to 67 patients who previously underwent either 2 total hip arthroplasties (THAs) or 2 total knee arthroplasties (TKAs). Results: Fifty-two patients (78%) responded to the survey. Thirty-four (65%) patients underwent staged, bilateral TKAs, and 18 (35%) patients underwent staged, bilateral THAs. Overall, 63% of patients preferred their SDD, 12% had no preference, and 25% preferred their ONS, with no difference in preference between TKA and THA groups. Those who preferred their SDD reported being more comfortable at home. Those who preferred their ONS felt their pain and concerns were better addressed. No differences were found in comfort, sleep quality, appetite, burden on family, return to function, feelings of being discharged too soon, overall experience, 30-day emergency department (ED) visits, or readmissions within 30 days between patients' SDD and ONS. There was a small statistically significant difference between patients' perception of safety between SDD and ONS. Conclusion: Our survey found that most patients reported a preference for SDD after TJA over ONS. Although there was a small difference in patient perception of safety, there were no differences in return to the ED or readmissions after SDD and ONS.

Transabdominal motor evoked potential neuromonitoring of lumbosacral spine surgery.

BACKGROUND CONTEXT: Transcranial Motor Evoked Potentials (TcMEPs) can improve intraoperative detection of femoral plexus and nerve root injury during lumbosacral spine surgery. However, even under ideal conditions, TcMEPs are not completely free of false-positive alerts due to the immobilizing effect of general anesthetics, especially in the proximal musculature. The application of transcutaneous stimulation to activate ventral nerve roots directly at the level of the conus medularis (bypassing the brain and spinal cord) has emerged as a method to potentially monitor the motor component of the femoral plexus and lumbosacral nerves free from the blunting effects of general anesthesia. PURPOSE: To evaluate the reliability and efficacy of transabdominal motor evoked potentials (TaMEPs) compared to TcMEPs during lumbosacral spine procedures. DESIGN: We present the findings of a single-center 12-month retrospective experience of all lumbosacral spine surgeries utilizing multimodality intraoperative neuromonitoring (IONM) consisting of TcMEPs, TaMEPs, somatosensory evoked potentials (SSEPs), electromyography (EMG), and electroencephalography. PATIENT SAMPLE: Two hundred and twenty patients having one, or a combination of lumbosacral spine procedures, including anterior lumbar interbody fusion (ALIF), lateral lumbar interbody fusion (LLIF), posterior spinal fusion (PSF), and/or transforaminal lumbar interbody fusion (TLIF). OUTCOME MEASURES: Intraoperative neuromonitoring data was correlated to immediate postoperative neurologic examinations and chart review. METHODS: Baseline reliability, false positive rate, true positive rate, false negative rate, area under the curve at baseline and at alerts, and detection of preoperative deficits of TcMEPs and TaMEPs were compared and analyzed for statistical significance. The relationship between transcutaneous stimulation voltage level and patient BMI was also examined. RESULTS: TaMEPs were significantly more reliable than TcMEPs in all muscles except abductor hallucis. Of the 27 false positive alerts, 24 were TcMEPs alone, and 3 were TaMEPs alone. Of the 19 true positives, none were detected by TcMEPs alone, 3 were detected by TaMEPs alone (TcMEPs were not present), and the remaining 16 true positives involved TaMEPs and TcMEPs. TaMEPs had a significantly larger area under the curve (AUC) at baseline than TcMEPs in all muscles except abductor hallucis. The percent decrease in TcMEP and TaMEP AUC during LLIF alerts was not significantly different. Both TcMEPs and TaMEPs reflected three preexisting motor deficits. Patient BMI and TaMEP stimulation intensity were found to be moderately positively correlated. CONCLUSIONS: These findings demonstrate the high reliability and predictability of TaMEPs and the potential added value when TaMEPs are incorporated into multimodality IONM during lumbosacral spine surgery.

Blood Flow Restriction Therapy Preserves Lower Extremity Bone and Muscle Mass After ACL Reconstruction.

BACKGROUND: Muscle atrophy is common after an injury to the knee and anterior cruciate ligament reconstruction (ACLR). Blood flow restriction therapy (BFR) combined with low-load resistance exercise may help mitigate muscle loss and improve the overall condition of the lower extremity (LE). PURPOSE: To determine whether BFR decreases the loss of LE lean mass (LM), bone mass, and bone mineral density (BMD) while improving function compared with standard rehabilitation after ACLR. STUDY DESIGN: Randomized controlled clinical trial. METHODS: A total of 32 patients undergoing ACLR with bone-patellar tendon-bone autograft were randomized into 2 groups (CONTROL: N = 15 [male = 7, female = 8; age = 24.1 ± 7.2 years; body mass index [BMI] = 26.9 ± 5.3 kg/m2] and BFR: N = 17 [male = 12, female = 5; age = 28.1 ± 7.4 years; BMI = 25.2 ± 2.8 kg/m2]) and performed 12 weeks of postsurgery rehabilitation with an average follow-up of 2.3 ± 1.0 years. Both groups performed the same rehabilitation protocol. During select exercises, the BFR group exercised under 80% arterial occlusion of the postoperative limb (Delfi tourniquet system). BMD, bone mass, and LM were measured using DEXA (iDXA, GE) at presurgery, week 6, and week 12 of rehabilitation. Functional measures were recorded at week 8 and week 12. Return to sport (RTS) was defined as the timepoint at which ACLR-specific objective functional testing was passed at physical therapy. A group-by-time analysis of covariance followed by a Tukey's post hoc test were used to detect within- and between-group changes. Type I error; α = 0.05. RESULTS: Compared with presurgery, only the CONTROL group experienced decreases in LE-LM at week 6 (-0.61 ± 0.19 kg, -6.64 ± 1.86%; P < 0.01) and week 12 (-0.39 ± 0.15 kg, -4.67 ± 1.58%; P = 0.01) of rehabilitation. LE bone mass was decreased only in the CONTROL group at week 6 (-12.87 ± 3.02 g, -2.11 ± 0.47%; P < 0.01) and week 12 (-16.95 ± 4.32 g,-2.58 ± 0.64%; P < 0.01). Overall, loss of site-specific BMD was greater in the CONTROL group (P < 0.05). Only the CONTROL group experienced reductions in proximal tibia (-8.00 ± 1.10%; P < 0.01) and proximal fibula (-15.0±2.50%,P < 0.01) at week 12 compared with presurgery measures. There were no complications. Functional measures were similar between groups. RTS time was reduced in the BFR group (6.4 ± 0.3 months) compared with the CONTROL group (8.3 ± 0.5 months; P = 0.01). CONCLUSION: After ACLR, BFR may decrease muscle and bone loss for up to 12 weeks postoperatively and may improve time to RTS with functional outcomes comparable with those of standard rehabilitation.

Greater Trochanteric Fixation Using Cable Plate Devices in Complex Primary and Revision Total Hip Arthroplasty.

Background: Successful fixation of the greater trochanter (GT) in total hip arthroplasty (THA) is a challenging task. A wide range of clinical results are reported in the literature despite advancements in fixation technology. Previous studies may have lacked adequate sample sizes to detect differences. This study evaluates nonunion and reoperation rates and determines factors influencing successful fixation of the GT using current-generation cable plate devices. Methods: This retrospective cohort study included 76 patients who underwent surgery requiring fixation of their GT and had at least 1-year radiographic follow-up. Indications for a surgery were periprosthetic fracture (n = 25), revision THA requiring an extended trochanteric osteotomy (n = 30), GT fracture (n = 3), GT fracture nonunion (n = 9), and complex primary THA (n = 3). Primary outcomes were radiographic union and reoperation. Secondary objectives were patient and plate factors influencing radiographic union. Results: At a mean radiographic follow-up of 2.5 years, the union rate was 76.3% with a nonunion rate of 23.7%. Twenty-eight patients underwent plate removal, reasons for removal were pain (n = 21), nonunion (n = 5), and hardware failure (n = 2). Seven patients had cable-induced bone loss. Anatomic positioning of the plate (P = .03) and number of cables used (P = .03) were associated with radiographic union. Nonunion was associated with a higher incidence (+30%) of hardware failure due to broken cable(s) (P = .005). Conclusions: Greater trochanteric nonunion remains a problem in THA. Successful fixation using current-generation cable plate devices may be influenced by plate positioning and number of cables used. Plate removal may be required for pain or cable-induced bone loss.

Optimal Blood Flow Restriction Occlusion Pressure for Shoulder Muscle Recruitment With Upper Extremity Exercise.

BACKGROUND: As blood flow restriction (BFR) utilization continues to rise, it is crucial to define optimal parameters for use. Currently unknown are the effects of occlusion level during BFR on muscle activity in the proximal shoulder. PURPOSE/HYPOTHESIS: The purpose of this study was to compare electromyographic amplitude (EMGa) of shoulder musculature during exercise using limb occlusion percentages (LOPs). The authors hypothesized that EMGa would increase concurrently with occlusion. STUDY DESIGN: Controlled laboratory study. METHODS: α Fifteen healthy adults were recruited and underwent 4 experimental sessions, performing 3 common rotator cuff exercises at low intensity (20% maximal strength) to failure in the following order: cable external rotation (ER), cable internal rotation (IR), and dumbbell scaption. Exercises were completed at a different occlusion pressure (0%, 25%, 50%, and 75% LOP- order randomized) applied at the proximal arm. EMGa was recorded from shoulder musculature proximal to the occlusion site and averaged across 5-repetition intervals and overall for the first 30 repetitions. An analysis of variance repeated on occlusion pressure followed by a Bonferroni post hoc test was used to compare EMGa, repetitions to fatigue, and ratings of discomfort (visual analog scale [VAS], 0-10) between occlusion pressures. The type 1 error was set at α = .05 for all analyses. RESULTS: Significant effects of the occlusion level on shoulder muscle EMGa were observed for all exercises (P < .05) with diminishing returns above 50% LOP (overall). For ER, elevations in EMGa were observed at ≥50% LOP for the anterior deltoid, middle deltoid, infraspinatus, and trapezius compared with 0% LOP (P < .05). For IR, elevations in EMGa were observed at ≥25% LOP for the anterior deltoid and trapezius compared with 0% LOP (P < .05). For the teres minor, a significant elevation in EMGa occurred at 75% LOP compared with 0%, 25%, and 50% LOP (P < .05). A decrease in EMGa was observed at ≥50% LOP compared with 0% LOP for the posterior deltoid (P < .05). For scaption, an increase in EMGa was observed at ≥25% LOP for the infraspinatus and teres minor muscles, at 75% LOP for the posterior deltoid, and at ≥50% LOP for the trapezius compared with 0% LOP (P < .05). Decreases in repetitions to failure relative to 0% LOP were observed at 75% LOP for ER (0%: 47 ± 5; 75%: 40 ± 2; P = .034), IR (0%: 82 ± 10; 75%: 64 ± 5; P = .017), and scaption (0%: 85 ± 9; 75%: 64 ± 6; P < .001). A significant linear increase in discomfort was observed for all exercises with increasing occlusion pressures (VAS: 0-10, 0% → 75% LOP; ER: 2.2 ± 0.4 → 7.2 ± 0.3; IR: 1.3 ± 0.2 → 6.1 ± 0.6; scaption: 1.3 ± 0.4 → 6.1 ± 0.4; P < .01). CONCLUSION: There are several differences in muscle activation about the shoulder based on exercise and occlusion when utilizing BFR. Increasing the percentage of limb occlusion leads to heightened EMGa with diminished returns past 50% LOP when considering muscle activation, discomfort, and achievable exercise volume. CLINICAL RELEVANCE: These findings may be used to refine upper extremity BFR guidelines.

Demographic and Lifestyle Factors Associated with Patient-Reported Acute COVID-19 Vaccine Reactivity.

Patient-reported vaccine reactivity (PRVR) is a major contributor to COVID-19 vaccine hesitancy. PRVR responses to the COVID-19 vaccine may be affected by several modifiable and non-modifiable factors that influence immune function. Understanding the effects of these factors on PRVR can aid in better educating patients on expectations, as well as formulating public health strategies to increase the levels of community vaccination.