Nav1.7 as a chondrocyte regulator and therapeutic target for osteoarthritis.

Osteoarthritis (OA) is the most common joint disease. Currently there are no effective methods that simultaneously prevent joint degeneration and reduce pain1. Although limited evidence suggests the existence of voltage-gated sodium channels (VGSCs) in chondrocytes2, their expression and function in chondrocytes and in OA remain essentially unknown. Here we identify Nav1.7 as an OA-associated VGSC and demonstrate that human OA chondrocytes express functional Nav1.7 channels, with a density of 0.1 to 0.15 channels per µm2 and 350 to 525 channels per cell. Serial genetic ablation of Nav1.7 in multiple mouse models demonstrates that Nav1.7 expressed in dorsal root ganglia neurons is involved in pain, whereas Nav1.7 in chondrocytes regulates OA progression. Pharmacological blockade of Nav1.7 with selective or clinically used pan-Nav channel blockers significantly ameliorates the progression of structural joint damage, and reduces OA pain behaviour. Mechanistically, Nav1.7 blockers regulate intracellular Ca2+ signalling and the chondrocyte secretome, which in turn affects chondrocyte biology and OA progression. Identification of Nav1.7 as a novel chondrocyte-expressed, OA-associated channel uncovers a dual target for the development of disease-modifying and non-opioid pain relief treatment for OA.

Patients With Segond Fracture Demonstrate Similar Rates of Return to Sport and Psychological Readiness After Anterior Cruciate Ligament Reconstruction: A Matched Cohort Study at Minimum 2-Year Follow-Up.

PURPOSE: To compare clinical outcomes, rate of return to sports, and psychological readiness among patients undergoing anterior cruciate ligament reconstruction (ACLR) with and without concomitant Segond fracture. METHODS: We retrospectively identified patients who underwent primary ACLR from January 2012 to December 2020 with minimum 2-year follow-up. Exclusion criteria were additional ligamentous injury, age <16 years, or a concomitant lateral augmentation procedure. Preoperative knee radiographs were reviewed to identify Segond fractures. Identified patients were matched 1:2 to controls by age/sex/body mass index/graft type. Charts were reviewed for pre- and postoperative knee stability. Surveys administered included preinjury sport participation and return status, Lysholm score, Tegner activity scale, and ACL-Return to Sport Index (ACL-RSI), a metric of psychological sport readiness. Multivariable logistic regression was conducted to identify predictors of return to sport. RESULTS: There were 120 patients who were included in the final analysis (40 Segond, 80 controls) at a mean follow-up of 5.7 ± 2.4 years. A total of 52.5% of patients received bone-patellar tendon-bone autograft. The overall rate of return to sport was 79.5% in the Segond group compared with an 83.8% rate of return in the control group (P = .569). In total, 48.7% of the Segond group and 56.8% of the control group returned to their preinjury level of sport (P = .415). Lysholm (89.6 ± 10.3 vs 85.4 ± 16.7, P = .296), Tegner (5.7 ± 1.8 vs 6.1 ± 2.2, P = .723), and ACL-RSI (62.2 ± 25.4 vs 56.6 ± 25.4, P = .578) scores were similar between Segond and control groups. There was a single graft failure in the Segond group 5 years' postoperatively. Increasing ACL-RSI score was significantly predictive of return to sport (P < .001). CONCLUSIONS: Patients who had an ACL tear and a concomitant Segond fracture who underwent isolated ACLR without lateral augmentation procedures had similar clinical outcomes and rates of return sport compared with a matched isolated ACLR control group at minimum 2-year follow-up. There was no significant difference in psychological readiness between groups as measured by the ACL-RSI. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Comparable Clinical and Functional Outcomes Between Osteochondral Allograft Transplantation and Autologous Chondrocyte Implantation for Articular Cartilage Lesions in the Patellofemoral Joint at a Mean Follow-up of 5 Years.

PURPOSE: To assess clinical outcomes and return to sport (RTS) rates among patients who undergo osteochondral allograft (OCA) transplantation and autologous chondrocyte implantation (ACI) or matrix-induced autologous chondrocyte implantation (MACI), for patellofemoral articular cartilage defects. METHODS: A retrospective review of patients who underwent an OCA or ACI/MACI from 2010 to 2020 was conducted. Patient-reported outcomes collected included visual analog scale for pain/satisfaction, Knee Injury and Osteoarthritis Outcome Score (KOOS), and RTS. The percentage of patients that met the patient acceptable symptom state for KOOS was recorded. Logistic regression was used to identify predictors of worse outcomes. RESULTS: A total of 95 patients were included (78% follow-up) with ACI or MACI performed in 55 cases (57.9%) and OCA in 40 (42.1%). A tibial tubercle osteotomy was the most common concomitant procedure for OCA (66%) and ACI/MACI (98%). Overall, KOOS pain was significantly poorer in OCA than ACI/MACI (74.7, 95% confidence interval 68.1-81.1 vs 83.6, 95% confidence interval 81.3, 88.4, P = .012), whereas the remaining KOOS subscores were nonsignificantly different (all P > .05). Overall, RTS rate was 54%, with no significant difference in return between OCA or ACI/MACI (52% vs 58%, P = .738). There were 26 (27%) reoperations and 5 (5%) graft failures in the entire group. Increasing age was associated with lower satisfaction in OCA and poorer outcomes in ACI/MACI, whereas larger lesion area was associated with lower satisfaction and poorer outcomes in ACI/MACI. CONCLUSIONS: Clinical and functional outcomes were similar in patients who underwent OCA or ACI/MACI for patellofemoral articular cartilage defects at a mean follow-up of 5 years. Patients who received OCA had a greater proportion of degenerative cartilage lesions and, among those with trochlear lesions, reported greater pain at final follow-up than their ACI/MACI counterparts. Overall, increasing age and a larger lesion size were associated with worse patient-reported outcomes. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Clinical outcomes following transtibial medial meniscal root repair are maintained at long-term follow-up.

PURPOSE: To evaluate long-term outcomes of patients treated with posterior medial meniscal root tear (PMMRT) repair through assessment of functional outcome scores and to identify patient surgical and magnetic resonance imaging (MRI) characteristics associated with improved outcomes. METHODS: This was a single-centre, retrospective study evaluating patients who had undergone a PMMR repair using a transtibial suture pullout technique with two locking cinch sutures. This was performed as a follow-up to previously published 2-year and 5-year outcome studies, using the same cohort. All patients from the prior short-term and midterm studies were invited to participate. Patient-reported outcome (PROs) scores, including the International Knee Documentation Committee (IKDC) and Lysholm scores, were collected. Previously collected demographic data were updated based on review of the electronic medical record. Patient outcomes were assessed preoperatively, as well as at 2-year, 5-year and 8-year postoperatively. MRI outcome measurements were assessed at 2-year and 5-year follow-ups. All statistical analysis was performed using SPSS version 26. RESULTS: Seventeen patients of the original 18 patients (94.4%) were included in the final analysis. Additionally, three patients who had additional ipsilateral surgery were excluded from the analysis of PROs. The IKDC score significantly increased from 44.7 ± 11.6 at preoperative baseline to 71.2 ± 21.3 at 8-year post-operation (p = 0.001). There were no significant differences in IKDC score between 2-year and 8-year follow-ups (p = n.s.) or 5-year and 8-year follow-ups (p = n.s.). The Lysholm score significantly increased from 49.6 ± 7.3 at preoperative baseline to 76.4 ± 17.2 at 8-year follow-up (p < 0.001). There was no significant difference in Lysholm scores between 2-year and 8-year follow-ups (p = n.s.) or 5-year and 8-year follow-ups (p = n.s.). A linear regression analysis found that 5-year IKDC scores were significantly correlated with 8-year IKDC scores (ß = 0.681, p = 0.038). At 8-year follow-up, four (23.5%) patients required additional procedures on their operative knee (one total knee arthroplasty conversion). CONCLUSION: Patients treated with repair of PMMRT had maintenance of clinical outcome improvements at long-term follow-up despite worsening MRI outcomes at short-term and medium-term follow-ups. While a high proportion of patients required additional procedures on their operative knee at 8-year follow-up, few of these patient's additional procedures were related to failure of their primary surgery. Providers and patients may expect durable clinical outcomes following the repair of PMMRT, irrespective of radiographic appearance. LEVEL OF EVIDENCE: Level IV.

Increased kinesiophobia leads to lower return to sport rate and clinical outcomes following osteochondral allograft transplantation of the knee.

PURPOSE: The purpose of this study is to describe the postoperative psychological state of patients following osteochondral allograft (OCA) transplantation in the knee and to determine whether patient-perceived kinesiophobia is associated with the rate of return to sport (RTS). METHODS: A retrospective review of the electronic medical record at a single institution was conducted for all patients that underwent OCA transplantation from January 2010 to 2020. Patient-reported outcomes including the visual analog scale (VAS), knee injury and osteoarthritis outcome score (KOOS) and the Tampa scale of kinesiophobia-11 (TSK-11) were collected. Patients were surveyed regarding their postoperative RTS status. RESULTS: A total of 38 patients (52.6% female) were included in our analysis. Overall, 24 patients (63.2%) returned to sport with 12 (50%) of these patients returning at a lower level of play. When comparing patients that return to sport to those that did not, patients that return had significantly superior KOOS pain (p = 0.019) and KOOS QOL (p = 0.011). Measures of kinesiophobia (TSK-11) were significantly higher among patients that did not return to sport (p = 0.014), while satisfaction (n.s.) and pain intensity (n.s.) were comparable between groups. Logistic regression models controlling for demographic factors, VAS pain scores and lesion size showed that for every one-point increase in TSK-11 kinesiophobia score, patients were 1.33 times more likely to return to sport at a lower level (p = 0.009). For every one-point increase in TSK-11 scores KOOS QOL decreased by 2.4 points (p < 0.001). CONCLUSION: Fear of reinjury decreases the likelihood that patients will return to their preoperative level of sport after OCA transplantation. Patients that do not return to sport report significantly greater fear of reinjury and inferior clinical outcomes, despite similar levels of satisfaction and pain compared to those that return. LEVEL OF EVIDENCE: Level III.

Patients who undergo tibial tubercle anteromedialization with medial patellofemoral ligament reconstruction demonstrate similar rates of return to sport compared to isolated MPFL reconstruction.

PURPOSE: To investigate the rate of return to sports and sport psychological readiness between patients who underwent isolated MPFLR (iMPFLR) compared to a matched cohort of patients who underwent MPFLR with anteromedializing tibial tubercle osteotomy (MPFLR/TTO). METHODS: Patients who underwent primary MPFLR with or without TTO for recurrent patellar instability were retrospectively reviewed from 2012 to 2020 at a single institution. Preinjury sport and work information, Kujala, Tegner, Visual Analogue Score for pain, satisfaction and MPFL-Return to Sport after Injury (MPFL-RSI) score were collected. Two readers independently measured the tibial tuberosity-trochlear groove distance, Caton-Deschamps index and Dejour classification for trochlear dysplasia. Patients in iMPFLR and MPFLR/TTO groups were matched 1:1 on age, sex, body mass index and follow-up length. Multivariate regression analysis was performed to determine whether the MPFL-RSI was associated with a return to sport. RESULTS: This study included 74 patients at mean follow-up of 52.5 months (range: 24-117). These groups returned to sport at similar rates (iMPFLR: 67.6%, MPFLR/TTO: 73.0%, not significant [ns]), though iMPFLR patients returned more quickly (8.4 vs. 12.8 months, p = 0.019). Rates of return to preinjury sport level were also similar (45.9% vs. 40.5%, ns). Patients with Dejour B/C took more time to return to sport compared to patients with mild/no trochlear pathology (13.8 vs. 7.9 months, p = 0.003). Increasing MPFL-RSI score was significantly predictive of the overall return to sport (odds ratio [OR]: 1.08, 95% confidence interval [CI] [1.03, 1.13], p < 0.001) and return to preinjury level (OR: 1.07, 95% CI [1.04, 1.13], p < 0.001). Most patients in iMPFLR and MPFLR/TTO groups resumed work (95.7% vs. 88.5%, ns), though iMPFLR patients who returned to preinjury work levels did so more quickly (1.7 vs. 4.6 months, p = 0.005). CONCLUSION: Patients who underwent MPFLR with anteromedializing TTO demonstrated similar rates of return to sport and psychological readiness compared to an isolated MPFLR matched comparison group, though iMPFLRs returned more quickly. Patients with more severe trochlear pathology required more time to return to sports. LEVEL OF EVIDENCE: Level III.

High Rate of Patient Satisfaction with Either Telemedicine or Traditional Office-Based Follow-Up Visit After Arthroscopic Shoulder Surgery.

Background: The purpose of this study was to determine if any differences exist in patient satisfaction with office-based visits versus telemedicine visits following arthroscopic shoulder surgery. Methods: Patients undergoing shoulder arthroscopy were prospectively enrolled for 1 year. Patient demographic and clinical data (including complication events) and second postoperative visit satisfaction data were recorded and analyzed for statistical significance. Results: Ninety-six (n = 96) patients met inclusion criteria. Fifty-four patients (56.3%) participated in a traditional in-person office visit, and 42 participated in a video visit (43.8%). No significant differences were found between office and video appointments in terms of overall care satisfaction (9.46 ± 0.9 vs. 9.55 ± 1.0, p = 0.67). Females were significantly less satisfied with their second postoperative visit compared with males (8.3 ± 2.3 vs. 9.3 ± 1.5, p = 0.035). Significantly more females would also have preferred a traditional in person office visit compared with males (91% vs. 67%, p = 0.009). Video appointment patients spent significantly more time with their surgeon than office visit patients (57.64 mean rank vs. 41.39 mean rank, p = 0.003). Discussion: Video visit patients required significantly less time overall for their visit and spent significantly more time with their surgeon, although did not demonstrate differences in satisfaction.

Segond fracture: an indicator for increased risk of lateral meniscus injury in patients with acute anterior cruciate ligament ruptures.

PURPOSE: The purpose of this study was to investigate the incidence and anatomic distribution of meniscus injury in patients who have sustained acute ACL injuries with and without concomitant Segond fracture. We hypothesized that patients who have sustained a torn ACL with a concomitant Segond fracture would have a higher incidence of lateral meniscal injuries than patients with an isolated ACL injury. METHODS: Patients who underwent ACL reconstruction from 2012 to 2022 were retrospectively reviewed. Segond fractures were identified on knee radiographs. Inclusion criteria were age 18-40, injury during sports activity, and reconstruction within 90 days of injury. Sports activity, anatomic location of meniscus injury, and meniscus treatment were documented. Multivariable regression was used to identify predictors of meniscus injury/treatment. RESULTS: There were 25 of 603 (4.1%) patients who had an ACL tear with concomitant Segond fracture. The incidence of lateral meniscus injury in the Segond group (72%) was significantly higher than in the non-Segond cohort (49%; p = 0.024). A significantly smaller proportion of medial meniscus injuries among patients with Segond fractures were repaired (23.1%) compared to the non-Segond group (54.2%; p = 0.043). Multivariate analysis found patients with Segond fractures to have increased odds of lateral meniscus injury (OR 2.68; [1.09, 6.60], p = 0.032) and were less likely to have medial meniscus injuries repaired (OR 0.35; [0.15, 0.81], p = 0.014). Additionally, males had increased odds of lateral meniscus injury (OR 1.54; [1.08 - 2.91], p = 0.017), which were more likely to require repair (OR 1.48; [1.02, 2.14], p = 0.038). CONCLUSIONS: Among acute ACL injuries, the incidence of lateral meniscus injury is greater among patients with Segond fractures. Patients with Segond fracture were less likely to undergo repair of medial meniscal injuries.

Concentration of synovial fluid biomarkers on the day of anterior cruciate ligament (ACL)-reconstruction predict size and depth of cartilage lesions on 5-year follow-up.

PURPOSE: The current investigation evaluated the relationship between the synovial fluid cytokine microenvironment at the time of isolated anterior cruciate ligament (ACL) reconstruction and the presence of subsequent chondral wear and radiologic evidence of osteoarthritis (OA) on cartilage-specific MRI sequences at a minimum of 5-year follow-up. METHODS: Patients who underwent primary ACL reconstruction with no baseline concomitant cartilage or meniscal defects and had synovial fluid samples obtained at the time of surgery were retrospectively identified. Patients with a minimum of 5 years of postoperative follow-up were contacted and asked to complete patient-reported outcome (PRO) measures including Visual Analog Scale (VAS) for pain, Lysholm Scale, Knee Injury and Osteoarthritis Outcome Score (KOOS), and Tegner Activity Scale, along with postoperative magnetic resonance imaging (MRI). The concentration of ten biomarkers that have previously been suggested to play a role in cartilage degradation and inflammation in the joint space was measured. Linear regression controlling for age, sex, and body mass index (BMI) was performed to create a model using the synovial fluid concentrations at the time of surgery to predict postoperative semiquantitative cartilage lesion size and depth on MRI at a minimum of 5 years follow up. RESULTS: The patients were comprised of eight males (44.4%) and ten females (55.6%) with a mean age at the time of surgery of 30.8 ± 8.7 years (range 18.2-44.5 years). The mean follow-up time was 7.8 ± 1.5 years post-operatively (range 5.7-9.7 years). MCP-1, VEGF, and IL-1Ra were found to have significant associations with the presence of postoperative cartilage wear (p < 0.05). No correlations were demonstrated among the biomarker concentrations at the time of injury with PRO scores at final follow-up (NS). CONCLUSION: Synovial fluid inflammatory biomarker concentrations at the time of injury can predict progression of early-stage post-traumatic osteoarthritis at a mean of almost 8 years post-operatively. Findings from this study may help identify treatment targets to alter the natural history of cartilage loss following anterior cruciate ligament injury. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Patients who undergo bilateral medial patellofemoral ligament reconstruction return to sport at a similar rate as those that undergo unilateral reconstruction.

PURPOSE: Lateral patellar instability is a debilitating condition not only to athletes, but also to a wide range of highly active individuals. Many of these patients experience symptoms bilaterally, though it is unknown how these patients fair with return to sports following a second medial patellofemoral ligament reconstruction (MPFLR). The purpose of this study is to evaluate the rate of return to sport following bilateral MPFLR compared to a unilateral comparison group. METHODS: Patients who underwent primary MPFLR with minimum 2-year follow-up were identified from 2014 to 2020 at an academic center. Those who underwent primary MPFLR of bilateral knees were identified. Pre-injury sport participation and Tegner score, Kujala score, Visual Analog Score (VAS) for pain, satisfaction, and MPFL-Return to Sport after Injury (MPFL-RSI) scale were collected. Bilateral and unilateral MPFLRs were matched in a 1:2 ratio based on age, sex, body mass index, and concomitant tibial tubercle osteotomy (TTO). A sub-analysis was performed regarding concomitant TTO. RESULTS: The final cohort consisted of 63 patients, including 21 patients who underwent bilateral MPFLR, matched to 42 unilateral patients at mean follow-up of 47 ± 27 months. Patients who underwent bilateral MPFLR returned to sport at a rate of 62% at a mean of 6.0 ± 2.3 months, compared to a unilateral rate of 72% at 8.1 ± 4.2 months (n.s.). The rate of return to pre-injury level was 43% among bilateral patients and 38% in the unilateral cohort. There were no significant differences in VAS pain, Kujala, current Tegner, satisfaction, and MPFL-RSI scores between cohorts. Approximately half of those (47%) who failed to return to sport cited psychological factors and had significantly lower MPFL-RSI scores (36.6 vs 74.2, p = 0.001). CONCLUSION: Patients who underwent bilateral MPFLR returned to sports at a similar rate and level compared to a unilateral comparison group. MPFL-RSI was found to be significantly associated with return to sport. LEVEL OF EVIDENCE: III.

No difference in clinical outcomes between operative and nonoperative management of minimally retracted proximal hamstring ruptures.

PURPOSE: The indications for surgical treatment of proximal hamstring ruptures are continuing to be refined. The purpose of this study was to compare patient-reported outcomes (PROs) between patients who underwent operative or nonoperative management of proximal hamstring ruptures. METHODS: A retrospective review of the electronic medical record identified all patients who were treated for a proximal hamstring rupture at our institution from 2013 to 2020. Patients were stratified into two groups, nonoperative or operative management, which were matched in a 2:1 ratio based on demographics (age, gender, and body mass index), chronicity of the injury, tendon retraction, and number of tendons torn. All patients completed a series of PROs including the Perth Hamstring Assessment Tool (PHAT), Visual Analogue Scale for pain (VAS), and the Tegner Activity Scale. Statistical analysis was performed using multi-variable linear regression and Mann-Whitney testing to compare nonparametric groups. RESULTS: Fifty-four patients (mean age = 49.6 ± 12.9 years; median: 49.1; range: 19-73) with proximal hamstring ruptures treated nonoperatively were successfully matched 2:1 to 27 patients who had underwent primary surgical repair. There were no differences in PROs between the nonoperative and operative cohorts (n.s.). Chronicity of the injury and older age correlated with significantly worse PROs across the entire cohort (p < 0.05). CONCLUSIONS: In this cohort of primarily middle-aged patients with proximal hamstring ruptures with less than three centimeters of tendon retraction, there was no difference in patient-reported outcome scores between matched cohorts of operatively and nonoperatively managed injuries. LEVEL OF EVIDENCE: Level III.

Treatment options for acute Rockwood type III-V acromioclavicular dislocations: a network meta-analysis of randomized controlled trials.

BACKGROUND: Acute Rockwood type III-V acromioclavicular (AC) dislocations have been treated with numerous surgical techniques over the years. The purpose of this study was to perform a network meta-analysis (NMA) of randomized controlled trials to quantitatively define the optimal treatment for AC dislocations requiring operative treatment. METHODS: A literature search of 3 databases was performed based on Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Randomized controlled trials comparing 1 of 10 treatments for acute Rockwood type III-V AC dislocations-nonoperative treatment, Kirschner wire fixation (KW), coracoclavicular screw fixation (Scr), hook plate (HP), open coracoclavicular cortical button (CBO), arthroscopic coracoclavicular cortical button (CBA), ≥2 coracoclavicular cortical buttons (CB2), isolated graft reconstruction (GR), cortical button with graft augmentation (CB-GR), and coracoclavicular and acromioclavicular fixation (AC)-were included. Clinical outcomes were compared using a frequentist approach to NMA, with statistical analysis performed using the R program. Treatment options were ranked using the P-score, which estimates the likelihood that the investigated treatment is the ideal method for an optimal result in each outcome measure on a scale from 0 to 1. RESULTS: Of 5362 reviewed studies, 26 met the inclusion criteria, with a total of 1581 patients included in the NMA. AC, CB-GR, GR, CB2, CBA, and CBO demonstrated superiority over HP, Scr, KW, and nonoperative treatment at final follow-up for the Constant-Murley score and Disabilities of the Arm, Shoulder and Hand score, with AC and CB-GR showing the highest P-scores for the Constant-Murley score (0.957 and 0.781, respectively) and GR and CBO showing the highest P-scores for the Disabilities of the Arm, Shoulder and Hand score (0.896 and 0.750, respectively). GR had the highest P-score for the visual analog scale score (0.986). HP, CB2, CB-GR, AC, CBA, and CBO demonstrated superiority in the coracoclavicular distance (CCD) and recurrence at final follow-up, with HP and CB2 having the highest P-scores for the CCD (0.798 and 0.757, respectively) and with GR and CB-GR having the highest P-scores for recurrence (0.880 and 0.855, respectively). KW and Scr showed the shortest operative times (P-scores of 0.917 and 0.810, respectively), whereas GR and CBA showed the longest operative times (P-scores of 0.120 and 0.097, respectively). CONCLUSIONS: Although there are multiple fixation options for acute Rockwood type III-V AC dislocations, adding AC fixation or graft augmentation likely improves functional outcomes and decreases the CCD and recurrence rate at final follow-up-at the expense of longer operative times.

Free-living Allen's hummingbirds (Selasphorus sasin) rarely use torpor while nesting.

For reproducing animals, maintaining energy balance despite thermoregulatory challenges is important for surviving and successfully raising offspring. This is especially apparent in small endotherms that exhibit high mass-specific metabolic rates and live in unpredictable environments. Many of these animals use torpor, substantially reducing their metabolic rate and often body temperature to cope with high energetic demands during non-foraging periods. In birds, when the incubating parent uses torpor, the lowered temperatures that thermally sensitive offspring experience could delay development or increase mortality risk. We used thermal imaging to noninvasively explore how nesting female hummingbirds sustain their own energy balance while effectively incubating their eggs and brooding their chicks. We located 67 active Allen's hummingbird (Selasphorus sasin) nests in Los Angeles, California and recorded nightly time-lapse thermal images at 14 of these nests for 108 nights using thermal cameras. We found that nesting females usually avoided entering torpor, with one bird entering deep torpor on two nights (2% of nights), and two other birds possibly using shallow torpor on three nights (3% of nights). We also modeled nightly energetic requirements of a bird experiencing nest temperatures vs. ambient temperature and using torpor or remaining normothermic, using data from similarly-sized broad-billed hummingbirds. Overall, we suggest that the warm environment of the nest, and possibly shallow torpor, help brooding female hummingbirds reduce their own energy requirements while prioritizing the energetic demands of their offspring.

Estimated Time to Maximum Medical Improvement of Intra-articular Injections in the Treatment of Knee Osteoarthritis-A Systematic Review.

PURPOSE: The purpose of the current study is to perform a systematic review of the literature and evaluate maximum medical improvement and minimal clinically important difference (MCID) of different injectables in the treatment of symptomatic knee osteoarthritis. METHODS: A systematic review was performed to evaluate maximum medical improvement and MCID in patients undergoing injections of different modalities for knee osteoarthritis. Demographic factors of the patients being reviewed were analyzed, with patient-reported outcomes as reported by visual analog scale (VAS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) being used to evaluate the clinical trajectory of patients receiving intra-articular injections. RESULTS: Overall, 79 (level of evidence I: 79) studies met inclusion criteria, with 8761 patients. Corticosteroid (CS) injections, middle molecular weight hyaluronic acid (MMW-HA), and leukocyte-rich platelet rich plasma (LR-PRP) injections reached their maximum pain control at 4 to 6 weeks after injection, as measured by VAS. The lowest VAS scores were reached for low molecular weight hyaluronic acid (LMW-HA), high molecular weight hyaluronic acid (HMW-HA), and leukocyte-poor platelet rich plasma (LP-PRP) by 3 months after injection. Similarly, the WOMAC scores were lowest at 4 to 6 weeks after CS and MMW-HA injections, and at 3 months after HMW-HA and LP-PRP injections. LR-PRP demonstrated the most prolonged pain relief relative to the other injection types, with the lowest VAS score of all groups measured at final follow-up. LP-PRP showed the lowest WOMAC scores at final follow-up, one year post-injection. CONCLUSION: PRP injections provide continued pain relief at up to 1 year after injection. Corticosteroids and hyaluronic acid have good efficacy and are suitable for many patients but lack this longevity. LEVEL OF EVIDENCE: Level I, a systematic review of Level I studies.

Transosseous-Equivalent/Suture Bridge Arthroscopic Rotator Cuff Repair in Combination With Late Postoperative Mobilization Yield Optimal Outcomes and Retear Rate: A Network Meta-analysis of Randomized Controlled Trials.

PURPOSE: The purpose of this study was to perform a network meta-analysis of the randomized controlled trials (RCTs) in the literature in order to assess the evidence defining the optimal combination of surgical technique single-row repair (SRR), double-row repair (DRR), or transosseous-equivalent/suture bridge (TOE/SB) arthroscopic rotator cuff repair (ARCR) and postoperative rehabilitation (early or late) protocol for ARCR. METHODS: The literature search was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomized SSR-early trials (RCTs) comparing SRR vs DRR vs TOE/SB ARCR techniques were included, as well as early vs late postoperative range of motion. Clinical outcomes were compared using a frequentist approach to network meta-analysis, with statistical analysis performed using R. The treatment options were ranked using the P-score. RESULTS: Twenty-eight studies comprising 2,181 total shoulders met the inclusion criteria. TOE/SB-late (odds ratio [OR], 0.19; 95% confidence interval [CI], 0.08-0.46) and DRR-late (OR, 0.25; 95% CI, 0.12-0.52) were found to significantly reduce the rate of retear, with TOE/SB-late resulting in the highest P-score for the American Shoulder and Elbow Surgeons (P-score: 0.7911) score and retear rate (P-score: 0.8725). DRR-early did not result in any significant improvements over the SRR-early group, except in internal rotation. There was no significant difference in forward flexion between groups, with almost equivalent P-scores. Furthermore, TOE/SB-early and TOE/SB-late trended toward worsening external rotation compared with the control. CONCLUSIONS: The current study suggests that rotator cuff repair using the TOE/SB technique and late postoperative mobilization yields the highest functional outcomes and lowest retear rate in the arthroscopic management of symptomatic rotator cuff tears. LEVEL OF EVIDENCE: Level I, meta-analysis of Level I studies.

Open Subpectoral Biceps Tenodesis May Be an Alternative to Arthroscopic Repair for SLAP Tears in Patients Under 30.

PURPOSE: The purpose of the current study is to compare the outcomes of open subpectoral biceps tenodesis (BT) to arthroscopic repair (AR) for SLAP tears in patients under the age of 30 years. METHODS: A retrospective review of patients under the age of 30 years who underwent either isolated BT or AR for a diagnosis of a SLAP tear between 2011 and 2019 was performed. Patients were included if they were >16 years old at the time of surgery, had an isolated SLAP tear involving instability of the biceps-labral anchor (types II-IV), were skeletally mature, and had a minimum follow-up of 12 months. The American Shoulder & Elbow Surgeons score, visual analog scale, Subjective Shoulder Value, patient satisfaction, willingness to undergo surgery again, revisions, and return to play (RTP) were evaluated. A P value of <.05 was considered statistically significant. RESULTS: Our study included 103 patients in total; 29 patients were treated with BT, and 74 were treated with AR. The mean age was 24.8 years, and the mean follow-up duration was 60 months. At final follow-up, there was no difference between treatment groups in any of the functional outcome measures assessed (P > .05). Overall, there was no significant difference in the total rate of RTP (BT: 76.3%, AR: 85%; P = .53), timing of RTP (BT: 8.8 months, AR: 9.4 months; P = .61), and total rate of RTP among overhead athletes (BT: 84.2%, AR: 83.3%; P > .99). Among those undergoing AR, 9 required a revision procedure (11.5%) compared to none treated with BT (P = .11). CONCLUSIONS: In patients under the age of 30 years with a symptomatic isolated SLAP tear, BT may be a reliable alternative to AR. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Anterior Shoulder Instability Part III-Revision Surgery, Rehabilitation and Return to Play, and Clinical Follow-Up-An International Consensus Statement.

PURPOSE: The purpose of this study was to establish consensus statements via a modified Delphi process on revision surgery, rehabilitation and return to play, and clinical follow-up for anterior shoulder instability. METHODS: A consensus process on the treatment using a modified Delphi technique was conducted, with 65 shoulder surgeons from 14 countries across 5 continents participating. Experts were assigned to one of 9 working groups defined by specific subtopics of interest within anterior shoulder instability. RESULTS: The primary relative indications for revision surgery include symptomatic apprehension or recurrent instability, additional intra-articular pathologies, and symptomatic hardware failure. In revision cases, the differentiating factors that dictate treatment are the degree of glenohumeral bone loss and rotator cuff function/integrity. The minimum amount of time before allowing athletes to return to play is unknown, but other factors should be considered, including restoration of strength, range of motion and proprioception, and resolved pain and apprehension, as these are prognostic factors of reinjury. Additionally, psychological factors should be considered in the rehabilitation process. Patients should be clinically followed up for a minimum of 12 months or until a return to full, premorbid function/activities. Finally, the following factors should be included in anterior shoulder instability-specific, patient-reported outcome measures: function/limitations impact on activities of daily living, return to sport/activity, instability symptoms, confidence in shoulder, and satisfaction. CONCLUSION: Overall, 92% of statements reached unanimous or strong consensus. The statements that reached unanimous consensus were indications and factors affecting decisions for revision surgery, as well as how prior surgeries impact procedure choice. Furthermore, there was unanimous consensus on the role of psychological factors in the return to play, considerations for allowing return to play, as well as prognostic factors. Finally, there was a lack of unanimous consensus on recommended timing and methods for clinical follow-up. LEVEL OF EVIDENCE: Level V, expert opinion.

Anterior Shoulder Instability Part II-Latarjet, Remplissage, and Glenoid Bone-Grafting-An International Consensus Statement.

PURPOSE: The purpose of this study was to establish consensus statements via a modified Delphi process on the Latarjet procedure, remplissage, and glenoid-bone grafting for anterior shoulder instability. METHODS: A consensus process on the treatment utilizing a modified Delphi technique was conducted, with 65 shoulder surgeons from 14 countries across 5 continents participating. Experts were assigned to one of 9 working groups defined by specific subtopics of interest within anterior shoulder instability. RESULTS: The technical approaches identified in the statements on the Latarjet procedure and glenoid bone-graft were that a subscapularis split approach should be utilized, and that it is unclear whether a capsular repair is routinely required. Furthermore, despite similar indications, glenoid bone-grafting may be preferred over the Latarjet in patients with bone-loss greater than can be treated with a coracoid graft, and in cases of surgeon preference, failed prior Latarjet or glenoid bone-grafting procedure, and epilepsy. In contrast, the primary indications for a remplissage procedure was either an off-track or engaging Hill-Sachs lesion without severe glenoid bone loss. Additionally, in contrast to the bone-block procedure, complications following remplissage are rare, and loss of shoulder external rotation can be minimized by performing the tenodesis via the safe-zone and not over medializing the fixation. CONCLUSION: Overall, 89% of statements reached unanimous or strong consensus. The statements that reached unanimous consensus were the prognostic factors that are important to consider in those undergoing a glenoid bone-grafting procedure including age, activity level, Hill-Sachs Lesion, extent of glenoid bone-loss, hyperlaxity, prior surgeries, and arthritic changes. Furthermore, there was unanimous agreement that it is unclear whether a capsular repair is routinely required with a glenoid bone graft, but it may be beneficial in some cases. There was no unanimous agreement on any aspect related to the Latarjet procedure or Remplissage. LEVEL OF EVIDENCE: Level V, expert opinion.

Anterior Shoulder Instability Part I-Diagnosis, Nonoperative Management, and Bankart Repair-An International Consensus Statement.

PURPOSE: The purpose of this study was to establish consensus statements via a modified Delphi process on the diagnosis, nonoperative management, and Bankart repair for anterior shoulder instability. METHODS: A consensus process on the treatment using a modified Delphi technique was conducted, with 65 shoulder surgeons from 14 countries across 5 continents participating. Experts were assigned to one of 9 working groups defined by specific subtopics of interest within anterior shoulder instability. RESULTS: The independent factors identified in the 2 statements that reached unanimous agreement in diagnosis and nonoperative management were age, gender, mechanism of injury, number of instability events, whether reduction was required, occupation, sport/position/level played, collision sport, glenoid or humeral bone-loss, and hyperlaxity. Of the 3 total statements reaching unanimous agreement in Bankart repair, additional factors included overhead sport participation, prior shoulder surgery, patient expectations, and ability to comply with postoperative rehabilitation. Additionally, there was unanimous agreement that complications are rare following Bankart repair and that recurrence rates can be diminished by a well-defined rehabilitation protocol, inferior anchor placement (5-8 mm apart), multiple small-anchor fixation points, treatment of concomitant pathologies, careful capsulolabral debridement/reattachment, and appropriate indications/assessment of risk factors. CONCLUSION: Overall, 77% of statements reached unanimous or strong consensus. The statements that reached unanimous consensus were the aspects of patient history that should be evaluated in those with acute instability, the prognostic factors for nonoperative management, and Bankart repair. Furthermore, there was unanimous consensus on the steps to minimize complications for Bankart repair, and the placement of anchors 5-8 mm apart. Finally, there was no consensus on the optimal position for shoulder immobilization. LEVEL OF EVIDENCE: Level V, expert opinion.

Posterior tibial tubercle measured by the sagittal TT-TG distance correlates with increased risk for patellofemoral chondral lesions.

PURPOSE: To evaluate the variation in tibial tubercle sagittal alignment in patients with and without patellofemoral (PF) cartilage wear. METHODS: This was a single-centre, retrospective review of patients that underwent a cartilage restoration procedure for isolated PF cartilage wear from 2014 to 2020. Patients were matched in a 1:2 ratio for age, sex and BMI to partial meniscectomy patients as controls. The sagittal TT-TG (sTT-TG) distance was measured on preoperative axial T2 magnetic resonance imaging (MRI) and was defined as the distance between a point at the nadir of the trochlear cartilage and the most anterior point of the tibial tubercle. RESULTS: One hundred and forty patients (47 cartilage restoration, 94 meniscectomy) were included. Mean age, BMI, and height for the total cohort were 34.01 ± 8.7, 26.6 ± 6.4, and 173.0 ± 17.7 respectively, with 78 males (55%) and 63 females (45%). There were no significant differences between groups for age, BMI or sex (n.s). The cartilage restoration group (- 2.5 mm ± 5.9) was found to have a significantly more posterior (negative) sTT-TG compared to the meniscectomy group (1.72 mm ± 6.7) (p < 0.001). Interrater reliability was excellent (ICC = 0.931, p < 0.001). Patients with less than - 3.4 mm sTT-TG were 2.74 times more likely to have a cartilage restoration procedure compared to those with greater than - 3.4 mm (OR 2.7, 95% CI 1.3-5.85). Patients with < - 10 mm posterior translation were 13.7× (CI 1.6-111.1) more likely to have a cartilage restoration procedure. CONCLUSION: Patients that underwent isolated cartilage restoration procedures had a significantly more posterior tibial tubercle than partial meniscectomy controls based on the sagittal TT-TG. The more posterior the tubercle, the more likely the patient had a cartilage restoration procedure. Surgeons should consider the sTT-TG measurement in patients presenting with anterior knee pain, particularly patellofemoral lesions. LEVEL OF EVIDENCE: III.