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 pre-and postoperatively. Patients were categorized by pre-operative (Pre-op) alignment (varus > 0°; valgus < 0°). Pre-op varus patients were then divided as follows based on post-operative alignment: neutral (VAR-NEUT, 0°±2); remaining in varus (VAR-rVAR, ≥3°); cross-over to valgus (VAR-CO, ≤-3°). Similarly, Pre-op valgus patients were divided as follows for post-operative alignment: neutral (VAL-NEUT, 0°±2); remaining in valgus (VAL-rVAL, ≤-3°); cross-over to varus (VAL-CO, ≥3°). The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS Jr.) survey scores were collected at pre-op as well as at 6-weeks, 3-, 6-, and 12-months post-op. Knee ROM was collected at 2 weeks, 6 to 12 weeks, and > 6-months post-op. An analysis of variance (ANOVA) repeated on time followed by a Bonferroni post-hoc test was used to compare outcomes for the postoperative alignment subgroups.

RESULTS

Pre-op Varus patients: Those in the VAR-CO group (overcorrected to -4.03° ± 1.95valgus) were observed to have lower KOOS Jr. scores at 3-, 6-, and 12-months post-op compared to those in the NEUT group (P < 0.05). This finding was paired with reduced ROM at 6 to 12 weeks post-op in the VAR-CO group compared to VAR-NEUT and VAR-rVAR (P < 0.05). Pre-op 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 post-op compared to VAL-NEUT and VAL-CO.

CONCLUSION

These findings indicate that post-operative 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.

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.

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.

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.

Robotic-Assisted Total Knee Arthroplasty Can Increase Frequency of Achieving Target Limb Alignment in Primary Total Knee Arthroplasty for Preoperative Valgus Deformity

Background

Robotic-assisted total knee arthroplasty (rTKA) has been shown to reduce the number of alignment outliers and to improve component positioning compared to manual TKA (mTKA). The primary purpose of this investigation was to compare the frequency of achieving target postoperative limb alignment and component positioning for rTKA vs mTKA.

Methods

A retrospective comparative study was performed on 250 patients undergoing primary TKA by 2 fellowship-trained arthroplasty surgeons. Surgeon A performed predominantly rTKA (103 cases) with the ROSA system (Zimmer Biomet, Warsaw, IN) and less frequently mTKA (44 cases) with conventional instrumentation. Surgeon B performed only mTKA (103 cases). Target limb alignment for surgeon A was 0° for all cases and for surgeon B was 2° varus for varus knees and 0° for valgus knees. Radiographic measurements were determined by 2 reviewers. Target zone was set at ± 2 degrees from the predefined target.

Results

When comparing rTKA to mTKA performed by different surgeons, there were no differences in the percentage within the target zone (57.28% vs 53.40%, P = .575), but rTKA did result in a greater percentage for cases with preoperative valgus (71.42% vs 44.12%, P = .031). Patient-reported Outcomes Measurement Information System Global-10 physical scores were statistically higher at both 3 (P = .016) and 6 months (P = .001) postoperatively for rTKA compared to mTKA performed by different surgeons.

Conclusions

Although experienced surgeons can achieve target limb alignment correction with similar frequency when comparing rTKA to mTKA for all cases, rTKA may achieve target limb alignment with more accuracy for preoperative valgus deformity.

Level of Evidence

Retrospective Cohort Study, Level III.

Validated Wearable Device Shows Acute Postoperative Changes in Sleep Patterns Consistent With Patient-Reported Outcomes and Progressive Decreases in Device Compliance After Shoulder Surgery

Purpose

To assess the utility of a validated wearable device (VWD) in examining preoperative and postoperative sleep patterns and how these data compare to patient-reported outcomes (PROs) after rotator cuff repair (RCR) or total shoulder arthroplasty (TSA).

Methods

Male and female adult patients undergoing either RCR or TSA were followed up from 34 days preoperatively to 6 weeks postoperatively. Sleep metrics were collected using a VWD in an unsupervised setting. PROs were assessed using the following validated outcome measures: Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function questionnaire; American Shoulder and Elbow Surgeons self-evaluation questionnaire; visual analog scale assessing pain; and Disabilities of the Arm, Shoulder and Hand questionnaire. Data were analyzed preoperatively and at 2-week intervals postoperatively with χ2 analysis to evaluate device compliance. Sleep metrics and PROs were evaluated at each interval relative to preoperative values within each surgery type with an analysis of variance repeated on time point. The relation between sleep metrics and PROs was assessed with correlation analysis.

Results

A total of 57 patients were included, 37 in the RCR group and 20 in the TSA group. The rate of device compliance in the RCR group decreased from 84% at surgery to 46% by 6 weeks postoperatively (P < .001). Similarly, the rate of device compliance in the TSA group decreased from 81% to 52% (P < .001). Deep sleep decreased in RCR patients at 2 to 4 weeks (decrease by 10.99 ± 3.96 minutes, P = .021) and 4 to 6 weeks postoperatively (decrease by 13.37 ± 4.08 minutes, P = .008). TSA patients showed decreased deep sleep at 0 to 2 weeks postoperatively (decrease by 12.91 ± 5.62 minutes, P = .045) and increased rapid eye movement sleep at 2 to 4 weeks postoperatively (increase by 26.91 ± 10.70 minutes, P = .031). Rapid eye movement sleep in the RCR group and total sleep in the TSA group were positively correlated with more favorable PROs (P < .05).

Conclusions

VWDs allow for monitoring components of sleep that offer insight into potential targets for improving postoperative fatigue, pain, and overall recovery after shoulder surgery. However, population demographic factors and ease of device use are barriers to optimized patient compliance during data collection.

Level of Evidence

Level IV, diagnostic case series.

A multimodal intraosseous infusion of morphine and ketorolac decreases early postoperative pain and opioid consumption following total knee arthroplasty

BACKGROUND

Multimodal pain management regimens and intraosseous infusion of morphine are two novel techniques that show promise in decreasing postoperative pain and opioid consumption following total knee arthroplasty. However, no study has analyzed the intraosseous infusion of a multimodal pain management regimen in this patient population. The purpose of our investigation was to examine the intraosseous administration of a multimodal pain regimen comprised of morphine and ketorolac during total knee arthroplasty with regard to immediate and 2-week postoperative pain, opioid pain medication intake, and nausea levels.

METHODS

In this prospective cohort study with comparisons to a historical control group, 24 patients were prospectively enrolled to receive an intraosseous infusion of morphine and ketorolac dosed according to age-based protocols while undergoing total knee arthroplasty. Immediate and 2-week postoperative Visual Analog Score (VAS) pain scores, opioid pain medication intake, and nausea levels were recorded and compared against a historical control group that received an intraosseous infusion of morphine alone.

RESULTS

During the first four postoperative hours, patients who received the multimodal intraosseous infusion experienced lower VAS pain scores and required less breakthrough intravenous pain medication than those patients in our historical control group. Following this immediate postoperative period, there were no additional differences between groups in terms of pain levels or opioid consumption, and there were no differences in nausea levels between groups at any time.

CONCLUSIONS

Our multimodal intraosseous infusion of morphine and ketorolac dosed according to age-based protocols improved immediate postoperative pain levels and reduced opioid consumption in the immediate postoperative period for patients undergoing total knee arthroplasty.

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.

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.

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.

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 (BFR^N=15, NOBFR^N=13) that, in conjunction with offseason training, performed 8wks of shoulder LIX [Throwing arm only; 2/wk, 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: IR0&90, ° ER0&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(N); 0.1-0.3, small(S); 0.3-0.5, moderate(M); 0.5-0.7, large(L); >0.7, very large(VL).

RESULTS

Following training, the BFR group experienced greater increases in shoulder-region lean mass [BFR: ↑227±60g, NOBFR: ↑75±37g, P=0.018, ES=1.0(VL)] and isometric strength for IR90° (↑2.4±2.3kg, P=0.041, ES=0.9VL). The NOBFR group experienced decreased shoulder flexion (↓1.6±0.8kg, P=0.007, ES=1.4VL) and IR at 0°(↓2.9±1.5kg, P=0.004, ES=1.1VL). The BFR group had a greater increase in achievable workload for the scaption exercise (BFR: ↑190±3.2kg, NOBFR: ↑90±3.3kg, P=0.005, 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=0.028, ES=0.8VL) as well as reduced forward (↓3.6°±2.1, P=0.001, ES=1.2VL) and lateral (↓4.6°±3.4, P=0.007, 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.

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.

Sex-related Anthropometrics in a Lower-Body Mobility Assessment Among Professional Soccer Athletes

Background

The functional movement screen (FMS™) and Y-balance test (YBT) are commonly used to evaluate mobility in athletes.

Purpose

The primary aim of this investigation was to determine the relationship between demographic and anthropometric factors such as sex, body composition, and skeletal dimension and scoring on YBT and FMS™ in male and female professional soccer athletes.

Study Design

Cross Sectional.

Methods

During pre-season assessments, athletes from two professional soccer clubs were recruited and underwent body composition and skeletal dimension analysis via dual-energy X-ray absorptiometry (DEXA) scans. Balance and mobility were assessed using the YBT and FMS™. A two-tailed t-test was used to compare YBT between sexes. Chi-square was used for sex comparisons of FMS™ scores. Correlation analysis was used to determine if body composition and/or skeletal dimensions correlated with YBT or FMS™ measures. Type-I error; α=0.05.

Results

40 Participants were successfully recruited: (24 males: 27±5yr, 79±9kg; |16 females: 25±3yr, 63±4kg). YBT: Correlations were found between anterior reach and height (r=-0.36), total lean mass (LM)(r=-0.39), and trunk LM(r=-0.39) as well as between posterolateral reach and pelvic width (PW)(r=0.42), femur length (r=0.44), and tibia length (r=0.51)(all p<0.05). FMS™: The deep squat score was correlated with height(r=-0.40), PW(r=0.40), LM(r=-0.43), and trunk LM (r =-0.40)(p<0.05). Inline lunge scores were correlated with height(r=-0.63), PW(r=0.60), LM(r=-0.77), trunk LM(r=-0.73), and leg LM(r=0.70)(all p<0.05). Straight leg raise scores were correlated with PW (r=0.45, p<0.05). Females scored higher for the three lower body FMS™ measures where correlations were observed (p<0.05).

Conclusions

Lower body FMS™ scores differ between male and female professional soccer athletes and are related to anthropometric factors that may influence screening and outcomes for the FMS™ and YBT, respectively. Thus, these anatomical factors likely need to be taken into account when assessing baseline performance and risk of injury to improve screening efficacy.

Level of Evidence

Level 3b.

Blood Flow Restriction Enhances Rehabilitation and Return to Sport: The Paradox of Proximal Performance

The use of blood flow restriction (BFR) within rehabilitation is rapidly increasing as further research is performed elucidating purported benefits such as improved muscular strength and size, neuromuscular control, decreased pain, and increased bone mineral density. Interestingly, these benefits are not isolated to structures distal to the occlusive stimulus. Proximal gains are of high interest to rehabilitation professionals, especially those working with patients who are limited due to pain or postsurgical precautions. The review to follow will focus on current evidence and ongoing hypotheses regarding physiologic responses to BFR, current clinical applications, proximal responses to BFR training, potential practical applications for rehabilitation and injury prevention, and directions for future research. Interestingly, benefits have been found in musculature proximal to the occlusive stimulus, which may lend promise to a greater variety of patient populations and conditions. Furthermore, an increasing demand for BFR use in the sports world warrants further research for performance research and recovery.

LEVEL OF EVIDENCE

Level V, expert opinion.

Anthropometric Factors Associated With Bone Stress Injuries in Collegiate Distance Runners: New Risk Metrics and Screening Tools?

BACKGROUND

Lower limb bone stress injury (BSI) of the pelvis, femur, and tibia is prevalent in collegiate track and field distance runners. Bone mineral density (BMD), body composition (BComp), and anthropometric parameters before initial collegiate injury have not been compared between runners with BSI and their noninjured counterparts.

PURPOSE

To characterize bone health in relation to BComp and anthropometric measurements from total-body dual x-ray absorptiometry (DXA) scans in collegiate male and female distance runners before BSI and develop BMD prediction models.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Distance runners (N = 79) from a single university track and field team were retrospectively enrolled into this study. The runners completed a DXA scan during the fall season (August-November) and participated in sport activities before the scan. Three months after scanning, electronic medical records were reviewed for the occurrence of BSI. An independent-sample t test was used to compare BMD (total and regional [spine, pelvis, and legs]), BComp (% body fat, fat mass, and lean mass), and anthropometric measurements (shoulder width and leg, arm, and trunk length) between runners with versus without BSI (included subgroup analysis by sex). Multiple linear regression with stepwise removal was used to determine variables most predictive of BMD.

RESULTS

Of the 79 enrolled participants (42 male, 37 female), 18 runners (22.8%; 11 female, 7 male) sustained a lower limb BSI. Compared with the noninjured group, injured runners had lower total and regional BMD (P < .001 for all) and shorter leg and arm lengths (P < .05 for both), whereas injured male runners had lower fat mass and injured female runners had lower lean mass in the legs (P < .05 for both). Injured runners' age-matched total BMD Z score (-0.1 ± 0.6) was considered clinically normal. BComp and anthropometric measures were predictive of total and regional BMD (P < .05; R 2 = 0.64-0.80; percentage error = 3.8%-4.8%).

CONCLUSION

The DXA scans of injured runners prior to incidence indicated lower BMD compared with noninjured runners. Shorter limb lengths, lower fat mass (male), and lower leg lean mass (female) may also be indicative of risk. Certain BComp and anthropometric measures were predictive of BMD.

Limb Occlusion Pressure Versus Standard Pneumatic Tourniquet Pressure in Open Carpal Tunnel Surgery – A Randomized Trial

Introduction: Pneumatic tourniquets are used extensively in orthopedic hand/wrist surgery. Complications, while rare, are associated with elevated pressure and duration of tourniquet use. Limb occlusion pressure (LOP) is the minimum tourniquet pressure at which arterial blood flow is restricted. Therefore, we performed a cross-sectional double-blinded randomized control trial to assess if there is a difference in post-operative pain at the surgical and tourniquet site between LOP and standard tourniquet pressure and if there is a difference in post-operative opioid usage.

Methods: A total of 44 patients (Age 60±13, 30 female, 14 male) were randomized into two groups (LOP, 191±14 mmHg | STP, 250 mmHg) of 22 patients controlling for gender (15 female, seven male). The primary outcome was a visual analog scale (VAS) for pain at the tourniquet and surgical sites, recorded for the first two weeks post-operative. Daily pain medication usage was recorded and quantified using oral morphine milligram equivalents (MME). A group-by-time generalized mixed-model ANOVA was used to detect within-group and between group (LOP vs STP) differences in VAS at the surgical and tourniquet sites as well as medication use. 

Results: LOP significantly decreased post-operative pain medication usage across the first week (-50%; p<0.05). Both groups had similar VAS pain at the surgery site, but the LOP group had 80% reduced pain at the tourniquet site when averaged across the first post-operative week (p<0.05). 

Conclusions: The use of LOP compared to STP elicits reduced post-operative pain at the tourniquet site and reduces post-operative pain medication use in the first post-operative week.

Relationship Between Pitch Volume and Subjective Report of Injury in High School Female Fast-Pitch Softball Pitchers

BACKGROUND

The relationship between pitch volume and injury is well-represented within baseball literature. However, the impact of softball pitch volume on injury epidemiology is limited.

HYPOTHESIS

The purpose was to determine if increased pitch volumes in high school-aged softball pitchers are related to increased rates of subjectively reported pain/injury. We hypothesized that pitchers with increased volumes would have higher pain/injury rates.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 4.

METHODS

A total of 28 female softball pitchers (aged 14-18 years) completed an online survey of questions pertaining to pitching history, pitch volume, and subjective report of pain or injury in the back, shoulder, and elbow. An independent-samples t test was used to (1) compare pitch volumes in those who reported pain in individual body regions (shoulder, elbow, back) compared with those who did not; (2) compare pitch volumes in those who reported pain in 0 or 1 of the regions of interest compared with 2 or 3 regions; and (3) compare the reported percentage of the past year that players reported playing through pain in players who averaged >85 compared with <85 pitches per game. Chi-square analysis was used to compare those who pitched either >85 or <85 pitches per game with regard to frequency of shoulder pain, elbow pain, back pain, seeking of medical attention, and actual injury diagnosis. Type I error was set at α = 0.05.

RESULTS

Weekly and yearly pitch counts were higher in those reporting pain or injury (YES) than those who did not (NO) in the shoulder (pitches per week: NO = 219 ± 35; YES = 429 ± 101; P = 0.027) (pitches per year: NO = 8876 ± 946; YES = 19,195 ± 4944; P = 0.022) and back (pitches per week: NO = 188 ± 16; YES = 426 ± 90; P = 0.014) (pitches per year: NO = 8334 ± 793; YES = 18,252 ± 4340; P = 0.027). Similar results were observed for those with pain or injury reported in 2 or 3 regions compared with 0 or 1 regions (pitches per week: NO = 220 ± 38; YES = 414 ± 95; P = 0.039) (pitches per year: NO = 8765 ± 1010; YES = 18,661 ± 4623; P = 0.028). Those reporting shoulder pain or injury also reported higher pitch counts per game (NO = 71.4 ± 5.2; YES = 83 ± 4; P = 0.049), and those reporting back pain also reported playing more games per week (NO = 2.7 ± 0.2; YES = 5.2 ± 1.1; P = 0.034). Those with pitch counts of >85/game were more than twice as likely to see a physician regarding pain/injury (P = 0.027) and reported playing through pain a higher percentage of the year (>85, 49.3% ± 10%; <85, 25.2% ± 6%; P < 0.05).

CONCLUSION

High pitching volumes commonly prevalent in high school-aged softball pitchers may be associated with increased pain/injury and appear related to cumulative volume.

CLINICAL RELEVANCE

This study provides recommendations for cumulative pitch volume guidelines in softball pitchers.

Pelvic region bone density, soft tissue mass, and injury frequency in female professional ballet dancers and soccer athletes

We recently observed a high prevalence of low pelvic bone mineral density (BMD) in female professional ballet performers. Because this population is susceptible to musculoskeletal overuse injuries, we aimed to determine which regions of the pelvis may be at greatest risk compared to general population females (GENPOP) as well as professional female soccer players (SOCCER, a comparison to other elite athletes regularly subjected to high degrees of loading). Three groups of age-matched females [(GENPOP; n = 38, 27±1yrs), (BALLET; single company, n = 36, 26±3yrs), (SOCCER; single NWSL® club, n = 34, 25±1yrs)] consented to have their BMD and body composition assessed (DEXA, GE®). In addition to soft tissue and total and regional BMD analyses, a segmental analysis of the pelvis was performed to determine site-specific BMD for the iliac fossa, iliac fossa/iliac crest/ilium combined, pubic bone, ischium, and sacrum. A mixed-model ANOVA followed by a Tukey's post-hoc test was used to compare the groups (Type-I error; α = 0.05). The BALLET group had lower pelvic BMD for all measures (Avg.%Diff. = 15%-27%, p<0.001) compared to the SOCCER group and for the ischium (Avg.%Diff.= 8%; p=0.007) and sacrum (Avg.%Diff. ​= ​7%; p = 0.028) compared to the GENPOP group. The BALLET group had lower lean mass for all measures compared to the other groups (Avg.%Diff. = 12%-18%; p < 0.01). Professional ballet performers exhibit reduced pelvic region soft tissue and site-specific BMD not previously detected using standard DEXA analyses. These findings highlight which pelvic regions may benefit from preventative strength training and/or nutritional interventions.

The Role of Fatigue in Return to Sport Testing Following Anterior Cruciate Ligament Reconstruction

BACKGROUND

Fatigue may play a role in anterior cruciate ligament (ACL) injury, but has not been incorporated into objective test batteries for return to sport decisions following ACL reconstruction (ACLR) surgery. The effect of fatigue on muscle function and performance following surgery and rehabilitation has been poorly studied.

PURPOSE/HYPOTHESIS

The purpose of this study was to assess the effect of fatigue on performance of various hop tests used in clinical rehabilitation settings by examining LSI scores. The authors hypothesized that participants will have worse limb symmetry index scores following the fatigue protocol and that the operative limb (ACLR) will have a greater decline in function than the non-operative limb (CON).

STUDY DESIGN

Cross-Sectional Study.

METHODS

Participants (n=21 [Male = 15, Female = 6]; AGE = 24.6 ± 9.3) were at least six months post ACLR and in rehabilitation. Testing was performed over two separate sessions in either a non-fatigued (NFS) or fatigued state (FS). In the FS, individuals performed a series of exercises to exhaust muscular endurance, strength, and power systems, after which they performed as battery of seven hop tests (single hop for distance, triple hop for distance, crossover hop for distance, 6-meter timed hop, lateral rotation hop for distance, medial rotation hop for distance, and vertical jump for height). A 2(limb) x 2(time) ANOVA was used to compare limbs between each state.

RESULTS

Differences between limbs (CON vs ACLR) were observed for all hop tests in the NFS whereby the ACLR limb was observed to have reduced performance (↓5.4-9.1%, p <0.05). When tested in the FS, significant differences in performance between limbs remained for only the crossover (↓4.9%), medial rotation (↓7.1%), lateral rotation (↓5.5%), and vertical hop (↓10.0%)(p<0.05). When comparing the NFS and FS states, only the CON limb was observed to have significant decreases in performance of the Triple Hop (↓7.4%), Crossover (↓8.7%), and Lateral Rotation (↓5.2%)(p<0.05).

CONCLUSIONS

Following ACL reconstruction, there appears to be a greater loss in jump performance in the CON limb in the FS. These findings suggest it may be crucial to consider and assess the endurance of both limbs rather than just the ACLR limb when determining readiness for return to play.

LEVEL OF EVIDENCE

Level 3.

Cement use in total knee arthroplasty: 40 versus 80 grams

BACKGROUND

Studies of cement use in total knee arthroplasty (TKA) have historically addressed mechanical properties and application strategies. Recently, cement technique has been studied as a means to reduce cost. We transitioned from opening two bags (80 grams) of cement to one bag (40 grams) of cement for primary TKA to improve cost efficacy. This study investigates the radiographic outcome and cost of TKAs performed with 40 versus 80 grams of cement.

METHODS

TKAs from January 2017 to January 2019 were evaluated. Cement mantle and implant alignment were assessed per the Modern Knee Society Radiographic Evaluation System at four months by three blinded reviewers. Data was analyzed according to quantity of cement used. Cement mantle quality at 16 implant zones was compared. Cost was evaluated.

RESULTS

163 patients (age 66.8 yrs. +/- 8.9, 51.5% female) underwent TKA with 80 grams of cement, while 142 patients (age 67.1 yrs. +/- 9.3, 56.3% female) underwent TKA utilizing 40 grams of cement. There was no significant difference in cement mantle quality. The most common zone of cement deficiency was the femoral posterior flange (9% in 40 gram group versus 4% in 80 gram group, p value = 0.08). There was no difference in implant size. Cost saving was calculated at $7,810 for the 40 gram group.

CONCLUSION

There was no difference in radiographic cement mantle appearance between primary knees performed with 40 or 80 grams of cement. Cement usage represents a target for cost saving and opportunity to increase the value of primary TKA. Based on the current incidence of TKA in the United States, cost savings could exceed 33 million dollars annually.

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.

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.

Predicting muscular strength using demographics, skeletal dimensions, and body composition measures

The purpose of this study was to develop an equation to predict strength for seven common resistance training exercises using anthropometric and demographic measures. One-hundred forty-seven healthy adults (74 males, 73 females, 35 ± 12 yr, 174 ± 10 cm, 88 ± 19 kg) volunteered to participate. Body composition values (regional/total) and body dimensions were assessed using dual-energy x-ray absorptiometry (DEXA). Subjects underwent the following maximal strength assessments: Leg Press, Chest Press, Leg Curl, Lat Pulldown, Leg Extension, Triceps Pushdown, and Biceps Curl. Multiple linear regression with stepwise removal was used to determine the best model to predict maximal strength for each exercise. Independent predictor variables identified (p < 0.05) were height (cm); weight (kg); BMI; age; sex (0 = F,1 = M); regional lean masses (LM,kg); fat mass (FM,kg); fat free mass (FFM,kg); percent fat (%BF); arm, leg, and trunk lengths (AL, LL, TL; cm); and shoulder width (SW,cm). Analyses were performed with and without regional measures to accommodate scenarios where DEXA is unavailable. All models presented were significant (p < 0.05, R² = 0.68–0.83), with regional models producing the greatest accuracy. Results indicate that maximal strength for individual resistance exercises can be reasonably estimated in adults.

Physiological Parameters of Bone Health in Elite Ballet Dancers

Stress fractures are common among elite ballet dancers whereby musculoskeletal health may be affected by energy balance and overtraining.

PURPOSE

This study aimed to characterize bone health in relation to stress fracture history, body composition, eating disorder risk, and blood biomarkers in professional male and female ballet dancers.

METHODS

A single cohort of 112 dancers (male: 55, 25 ± 6 yr; female: 57, 24 ± 6 yr) was recruited. All participants underwent bone and body composition measures using dual-energy x-ray absorptiometry. In a subset of our cohort (male: 30, 24 ± 6 yr; female, 29, 23 ± 5 yr), a blood panel, disordered eating screen, menstrual history, and stress fracture history were also collected. Age-matched Z scores and young-adult T scores were calculated for bone mineral density (BMD) and body composition. Independent-samples t-tests and Fisher's exact tests were used to compare BMD, Z-scores, T scores, and those with and without history of stress fractures. A 1 × 3 ANOVA was used to compare BMD for those scoring 0-1, 2-6, and 7+ using the EAT26 questionnaire for eating disorder risk. Regression was used to predict BMD from demographic and body composition measures.

RESULTS

Female dancers demonstrated reduced spinal (42nd percentile, 10%T < -1) and pelvic (16th percentile, 76%T < -1) BMD. Several anthropometric measures were predictive of BMD (P < 0.05, r = 0.65-0.81, standard error of estimate = 0.08-0.10 g·cm, percent error = 6.3-8.5). Those scoring >1 on EAT26 had lower BMD than did those with a score of 0-1 (P < 0.05).

CONCLUSIONS

Professional female ballet dancers exhibit reduced BMD, fat mass, and lean mass compared with the general population whereby low BMD and stress fractures tend to be more prevalent in those with a higher risk of disordered eating. Anthropometric and demographic measures are predictive of BMD in this population.

DEXA overestimates bone mineral density in adults with knee replacements

We examined bone mineral density (BMD) measurements made by dual-energy-xray-absorptiometry (DEXA) taken from 100 patients (♂46/♀54, 66±6yr) who previously underwent single total-knee arthroplasty (TKA) to determine if automated software-based artifact detection (ASAD) adequately removes implant artifact from the DXA image before analysis and if potential inaccuracies could be overcome through manual artifact correction (MAC). We also sought to determine if software-based inaccuracies would result in fracture risk misclassification (Low-BMD/Osteopenia = Young-Adult T-Score < −1). Select Results: When using ASAD, limbs with implants had higher BMD (+12.0 ​± ​1.7%, p ​< ​0.001) compared to control limbs resulting in a 2.5 ​± ​0.2% overestimation of total-body BMD (single implant). Consequently, the prevalence of osteopenia in 95% of patients who would have been observed to have low leg BMD (18/19 patients) and 80% of those found to have low total-body BMD (4/5 patients) would have gone un-diagnosed. This overestimation was eliminated when using MAC. These results reveal a potential issue with ASAD for total-body DEXA scans in TKA patients and highlight the importance of careful review and MAC in those with joint replacements before making diagnostic decisions.

Acute Physiologic Effects of Performing Yoga in The Heat on Energy Expenditure, Range of Motion, and Inflammatory Biomarkers

Performing yoga in a heated environment (HY) is a popular exercise mode purported to improve range of motion (ROM), body composition, and aerobic fitness. The purpose of this investigation was to compare a session of HY to room temperature yoga (RTY) with regards to ROM, oxygen consumption, caloric expenditure, and biomarkers of acute stress and inflammation. Sixteen experienced yoga practitioners (F14, M2; 40 ± 11yr; 22.6 ± 1.8 kg/m2) completed a 1-hour standardized Bikram sequence in HY (105°F, 40°C) and RTY (74°F, 23.3°C) conditions (order of conditions randomized, humidity standardized at 40%). Intra-exercise metabolic gas exchange and heart rate (HR) was monitored using a metabolic cart. ROM measures were taken pre and post-exercise at the elbow, shoulder, hip, and knee. Cytokines interleukin 6,10 (IL-6, IL-10) and tumor-necrosis-factor alpha (TNF-α) were analyzed from blood samples collected pre- and 30-minutes post-exercise. Intra-exercise metabolic gas exchange and heart rate (HR) was monitored using a metabolic cart. Both bouts elicited similar acute changes in ROM although HY elicited a greater increase in hip abduction (RTYΔ° = 2.3 ± 1.3|HYΔ° = 6.6 ± 1.5; p < 0.05). Mean VO2, peak VO2, %VO2max, HR, and kcal expenditure did not differ between conditions. RER was lower during the HY (RTY = 0.95 ± 0.02| HY = 0.89 ± 0.02; p < 0.05) with a concomitant elevation in fat oxidation (RTY = 0.05 ± 0.01|HY = 0.09 ± 0.01, g·min-1; p < 0.05) and decrease in carbohydrate oxidation (RTY = 0.51 ± 0.04|HY = 0.44 ± 0.03, g·min-1; p < 0.05). Serum IL-6 was increased (15.5 ± 8.0-fold) following HY only (p < 0.05). HY does not significantly elevate aerobic energy cost compared to RTY but may acutely increase fat substrate utilization and hip ROM. Future studies remain needed to establish dose-response relationships for including HY or RTY into well-rounded fitness programs.

Clinical outcome evaluation of intraosseous vancomycin in total knee arthroplasty

Background

Vancomycin is a commonly used prophylactic antibiotic for total joint replacement surgery to protect against methicillin-resistant Staphylococcus aureus. Studies have suggested intraosseous (IO) infusions provide superior local tissue antibiotic concentration compared with intravenous (IV) access in total knee arthroplasty (TKA). We reviewed patients receiving IO vancomycin before TKA, comparing complication rates to a matched group receiving IV prophylactic vancomycin.

Methods

Retrospective review of TKA patients administered IO vancomycin (500 mg vancomycin in 200 mL normal saline), September 1, 2018 to March 1, 2019, was compared with TKAs performed with prophylactic IV vancomycin, January 1, 2018 to August 31, 2018. Before incision, an IO needle was inserted into the tibial tubercle region, delivering 100 mL of the mixed vancomycin solution. The needle was then removed and inserted into the distal femur, delivering 100 mL of the solution. Evaluation included preoperative and postoperative creatinine values, tourniquet time, and knee-related 30-day and 90-day complications. Data for primary and revision TKA surgery cases were analyzed independently.

Results

There were 100 primary and 29 revision TKA cases in the control (IV) arm and 100 primary and 19 revision TKA cases in the intervention (IO) arm, comprising a study group of 248 cases. There were fifteen 30-day complications and eighteen 90-day complications overall. No significant differences in the complication rate or creatinine values were identified between IO and IV groups.

Conclusions

IO vancomycin has an adequate safety profile in primary and revision TKA, eliminating the logistical challenge of timely prophylactic antibiotic administration.

The Usefulness of Meta-Analyses to Hip and Knee Surgeons

BACKGROUND

Comprehensive systematic reviews of results from homogenous or heterogeneous clinical trials, meta-analyses are used to summarize and to interpret studies. Proponents believe that their use can increase study power and improve precision results. Critics emphasize that heterogeneity between studies and bias of individual studies compromise the value of results. The methodology of meta-analyses has improved over time, utilizing statistical analysis to reduce bias and examining heterogeneity. With an increasing trend of meta-analyses in orthopaedic literature, this study aimed to investigate quality and clinical utility of meta-analyses for total knee arthroplasty and total hip arthroplasty.

METHODS

A systematic review of total knee arthroplasty and total hip arthroplasty meta-analyses in 3 major orthopaedic journals from January 2000 to August 2017 was performed. Three authors independently reviewed eligible meta-analyses. A quality assessment was conducted using the Oxman-Guyatt Index. Reporting quality was assessed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). Two high-volume, fellowship-trained, attending surgeons specializing in total hip arthroplasty and total knee arthroplasty independently, in a blinded fashion, reviewed 24 of the highest-scored meta-analyses.

RESULTS

There were 114 studies meeting eligibility criteria, 25 published from 2000 to 2009 and 89 published from 2010 to 2017, a 3.6-fold increase. The mean Oxman-Guyatt Index score was 3.89 points, with 12 high-quality studies, 87 moderate-quality studies, and 15 low-quality studies. The mean PRISMA score for all meta-analyses was 22.2 points, with 79% classified as low to moderate. Only 23 studies listed the Level of Evidence, and 8 were Level-I studies and 9 were Level-II studies. Studies with >15 randomized controlled trials were associated with higher PRISMA and Oxman-Guyatt Index scores. In 12 articles, we were unable to decipher the types of studies included. Only 39.4% of studies showed the risk of bias. Of the 24 studies identified as high quality per the PRISMA statement, 71% were determined to be either clinically unimportant or inconclusive.

CONCLUSIONS

The number of total hip arthroplasty and total knee arthroplasty meta-analyses has markedly increased over the past decades. The majority of published meta-analyses from 3 major orthopaedic journals were not performed in accordance with established PRISMA guidelines.

CLINICAL RELEVANCE

Many published meta-analyses are low to moderate quality, and clinicians should cautiously draw conclusions from poorly executed meta-analyses.

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.

Single-stage versus two-stage revision anterior cruciate ligament reconstruction: a systematic review

Importance

Despite advances in surgical techniques and postoperative rehabilitation, long-term anterior cruciate ligament (ACL) graft rupture rate remains high. The increasing number of primary ACL reconstructions in an ageing population will lead to increasing revision reconstructions. Revision cases may have higher failure rates and worse patient-reported outcomes compared with primaries. While two-stage revisions may be indicated in certain complex cases, whether this is comparatively equivalent or even superior to revisions done in a single stage would assist preoperative planning.

Objective

The objective of this systematic review was to analyse and compare patient-reported outcomes and failure rate of single-stage versus two-stage revision ACL reconstruction.

Evidence review

Using PubMed, MEDLINE Complete and Ovid MEDLINE databases, a review was performed using Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines to identify level I–IV outcomes of revision ACL reconstruction with a minimum follow-up of 24 months.

Findings

Three studies reported outcomes of two-stage revisions with mean follow-up of 61.6 months, while 21 studies reported single-stage revisions with mean follow-up of 47.4 months. Pooled rate of two-stage revisions was 3.1% compared with 6.8% in single-stage (p=0.068). Clinical failure was reported in 5.1% of 79 two-stage patients compared with 13.8% of 533 single-stage patients (p<0.05). Within the single-stage cohort, there was a greater clinical failure rate (+8.7%, p<0.05) for patients with less than 48 months follow-up. Those with > 48 months follow-up had a higher rerupture rate (+5%, p<0.05) and a significantly greater sum of squared deviations (p<0.05) compared with those with < 48 months follow-up. Patient-reported outcomes have demonstrated two-stage revision patients with higher IKDC A and B scores than single-stage.

Conclusions and relevance

Although two-stage revisions may be performed in more complex cases, there are limited short-term data available regarding their outcomes. Two-stage revisions demonstrated comparable clinical outcomes and lower rate of revision surgery and clinical failure compared with single-stage revisions. Studies with shorter follow-up (24–48 months) showed higher clinical failure rates. Those with longer follow-up (>48 months) showed higher graft rerupture rates. The decision to perform staged reconstruction should made on whether adequate tunnel placement and fixation can be established in a single setting.

Level of evidence

Level IV.

A Biomechanical Comparison of Fifth Metatarsal Jones Fracture Fixation Methods

BACKGROUND

Fifth metatarsal base fractures of the metaphyseal-diaphyseal watershed junction (Jones fracture) are commonly treated with surgical fixation in athletes. Intramedullary screw fixation remains the most utilized construct, although plantar-lateral plating is an alternative. Purpose/Hypothesis: The purpose was to compare the mechanical strength of fracture fixation between an intramedullary screw and plantar-lateral plating. The hypothesis was that plantar-lateral plate fixation would allow for more cycles and higher peak loads before failure, as well as less fracture gapping, than would an intramedullary screw in cadaveric foot specimens with simulated Jones fractures exposed to cantilever bending.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twelve pairs of male cadaver feet were separated into 2 groups (plate or screw) to conduct contralateral comparative testing of 2 devices with equally numbered right and left feet. For each fifth metatarsal, an osteotomy with a microsagittal saw was created to simulate a Jones fracture. The plate group underwent fixation with a 3.0-mm 4-hole low-profile titanium plate placed plantar-laterally with 3 locking screws and 1 nonlocking screw. The screw group underwent fixation with a 40- or 45-mm × 5.5-mm partially threaded solid titanium intramedullary screw. After fixation, the metatarsals were excised for biomechanical testing. Cyclic cantilever failure testing was conducted with a gradient-cycle method. Sinusoidal loading forces were applied, increasing by 5.0-pound-force increments per 10 cycles, until each specimen experienced mechanical failure of implant or bone. Failure mode, number of cycles to failure, peak failure load, gap width at the last mutual prefailure loading, and video data were recorded. Paired 2-tailed t test (α = 0.05) was used to compare groups ( P < .05 set for significance).

RESULTS

Failure mode in both groups occurred predominantly at the bone-implant interface. Plate fixation resulted in significantly higher mean ± SD values for cycles to failure (63.9 ± 27.0 vs 37.3 ± 36.9, P = .01) and peak failure load (159.2 ± 60.5 N vs 96.5 ± 45.8 N, P = .01), with a significantly lower mean gap width (0.0 ± 0.0 mm vs 3.2 ± 2.4 mm, P < .01).

CONCLUSION

As compared with intramedullary screw fixation, plantar-lateral plating allowed for greater cycles to failure and peak load before failure, as well as less gap width, when applied to cadaver foot specimens with simulated Jones fractures exposed to cantilever bending in a load frame.

CLINICAL RELEVANCE

Early return to play among athletes before Jones fracture union is associated with increased risk of failure. This study introduces a plantar-lateral plating construct that performed more favorably than intramedullary screw fixation when applied to simulated Jones fractures in cadaveric foot specimens. Further clinical comparative studies are needed to assess the clinical use of this construct.

Plantar Plating for the Treatment of Proximal Fifth Metatarsal Fractures in Elite Athletes

Proximal fifth metatarsal fractures, zones II and III, are commonly treated surgically, especially in elite athletes. Intramedullary screw fixation remains the most used construct despite nonunion and refracture. High tensile forces on the plantar-lateral aspect of the fifth metatarsal are difficult to control, and intramedullary screw fixation depends on ideal screw position, length, and width. The authors present a plantar plating technique with cancellous bone autograft for zones II and III proximal fifth metatarsal fractures. Rotational instability and plantar-lateral gapping are resisted by applying a compression plate to the tension side of the fracture, eliminating causes for failure. [Orthopedics. 2017; 40(3):e563-e566.].

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.

Echocardiographic and Blood Pressure Characteristics of First-Year Collegiate American-Style Football Players

Echocardiographic (echo) and blood pressure (BP) reference values may help identify athletes at cardiovascular risk, yet benchmarks are inadequate for collegiate American-style football (ASF) players. Our purpose was to describe echo characteristics and BP values in collegiate ASF athletes compared with normal. First-year players (n = 80, age = 18 ± 1 years, height = 186 ± 7 cm, weight = 100.1 ± 22.0 kg, body mass index = 28.7 ± 5.0), body surface area [BSA] = 2.24 ± 0.25; percentage fat = 16.5 ± 9.7%) were measured for systolic and diastolic BP, and underwent echo procedures by a certified sonographer. Data analyses included simple statistics, Pearson r, frequencies in normal ranges, and t test; α = 0.05. Selected echo measurements (and indexed by BSA) were: left ventricular (LV) internal diameter diastole = 5.3 ± 0.5 cm (2.4 ± 0.3); left atrial diameter = 3.9 ± 0.5 cm (1.8 ± 0.2): LV end-diastolic volume = 138 ± 30 ml (62 ± 11); septal wall thickness = 1.0 ± 0.2 cm (0.5 ± 0.1); LV posterior wall thickness = 1.0 ± 0.1 cm (0.5 ± 0.1), LV mass = 212 ± 46 g (95 ± 18); and relative wall thickness = 0.39 ± 0.07. Correlations between BSA and echo variables were significant (r = 0.26 to 0.50). Indexing by BSA reduced percentages above reference ranges from 36% to 7%. Septal wall thickness index was significantly greater in black (0.5 ± 0.1) than nonblack (0.4 ± 0.1) athletes. Fifty-nine athletes were hypertensive or prehypertensive, and diastolic BP was significantly greater in black (76 ± 10 mm Hg) compared with nonblack athletes (71 ± 8 mm Hg). ASF athletes demonstrated LV wall thicknesses and cavity sizes consistent with sport-training hypertrophy but which were unremarkable when indexed by BSA. Ethnicity generally did not influence echo variables. No ASF players were identified with cardiac dysfunction or disease.