Improved functional outcome and tuberosity healing in patients treated with fracture stems than nonfracture stems during shoulder arthroplasty for proximal humeral fracture: a meta-analysis and systematic review.

BACKGROUND: Proximal humeral fractures are difficult injuries to treat and obtain satisfactory outcomes. For those treated with arthroplasty, humeral fracture stems have been popular due to better ability for reduction and fixation of tuberosities. This study aims to investigate the outcomes of fracture stems in shoulder arthroplasty for proximal humeral fracture and the comparison of outcomes between fracture vs. nonfracture stems. METHODS: A meta-analysis was conducted with a multidatabase search (PubMed, OVID, EMBASE, Medline) according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines on May 19, 2020. Data from all published literature meeting inclusion criteria were extracted and analyzed. FINDINGS: Eleven studies were included for analysis, including 383 hemiarthroplasties (HA) (294 fracture stems, 89 nonfracture stems) and 358 reverse total shoulder arthroplasties (RTSA) (309 fracture stems, 49 nonfracture stems). At the final follow-up, meta-analysis shows favorable overall ASES score in all fracture stem prosthesis (mean = 74.0, 95% confidence interval [CI]: 69.3-78.7), Constant-Murley score (mean = 67.2, 95% CI: 61.6-72.8), external rotation (mean difference [MD] = 7°, 95% CI: 3°-10°, P < .001), and forward flexion (MD = 17°, 95% CI: 10°-25°, P < .001). Pooled proportion (PP) of greater tuberosity healing (PP = 0.786, 95% CI: 0.686-0.886) was high, whereas all-cause revisions (PP = 0.034, 95% CI: 0.018-0.061) remained low. With the exception of RTSA scapular notching (PP = 0.109, 95% CI: 0.020-0.343), other complication metrics had PP of ≤0.023. In the 4 studies comparing fracture (138 HA, 54 RTSA) vs. nonfracture stems (89 HA, 49 RTSA), fracture stems had statistically significant better American Shoulder and Elbow Surgeons scores (MD = 14.29, 95% CI: 8.18-20.41, P < .001), external rotation (MD = 6°, 95% CI: 2°-9°, P = .003), forward flexion (MD = 16°, 95% CI: 7°-24°, P < .001), and greater tuberosity healing (odds ratio = 2.20, 95% CI: 1.28-3.77, P = .004). There was no statistically significant difference in complications. CONCLUSION: Fracture stems showed promising overall clinical outcomes with low complication rates in treating proximal humeral fractures. The use of fracture stems is also associated with greater chance of tuberosity healing compared with nonfracture stems. There is increasing evidence to suggest the superiority of fracture stems over nonfracture stems in clinical outcomes, while maintaining similar complication rates.

Time to surgery for hip fracture patients in a rural orthopaedic referral hospital.

PROBLEM: It is well established that shorter surgical waiting time for hip fracture patients improves outcomes. We identify and quantify time to surgery for hip fracture patients in a rural hospital. DESIGN: Retrospective observational study. SETTING: : A sixty-bed rural referral hospital with an orthopaedic service. Data were collected for 57 patients 50 years and older who had surgery for Muller AO type 31-A and 31-B fractures at Bega Hospital in 2012. KEY MEASURES FOR IMPROVEMENT: Time to surgery from presentation was compared for patients who presented directly to Bega hospital to those that were transferred from a peripheral hospital. STRATEGIES FOR CHANGE: To quantify contributing factors to surgical delay will help identify areas for future improvement. EFFECTS OF CHANGE: Delay to surgery from presentation was significantly greater for transferred patients (58 hours), compared with direct presentations (41 hours). Mean time for patient transfer was 23 hours. Thirty-five per cent of patients had their operation within 36 hours from presentation. LESSONS LEARNT: The time to surgery for most transfer and direct presentation patients fell outside current guidelines. In our geographically large referral network, delay to surgery was significantly influenced by time to transfer. Based on previously published research, surgery for our hip fracture patients should be expedited. We therefore recommend priority transfer for these significantly injured patients and dedicated emergency operating lists to perform this surgery in a timely manner.

Triangular fibrocartilage complex injury: outcomes of operative and non-operative management.

OBJECTIVE: The prevalence TFCC injuries has increased over time. However, there remains a lack of understanding of its natural history. Along with the paucity of evidence on treatment options, there is lack of consensus on how best to manage them. This is a retrospective study with subgroup cohort analysis, examining variables and management options associated with patient-reported disability and pain. METHODS: Patients from a metropolitan health network who have been referred for Magnetic Resonance Imaging (MRI) of the wrist between 2010 and 2019 and identified to have TFCC injury, were followed up to determine patient-reported outcomes. Disability of arm shoulder and hand scores (DASH) and visual assessment pain scale (VAS) were used to measure disability and pain respectively. An 'excellent' DASH and VAS scores were defined as ≤10 and ≤2, respectively. RESULTS: One hundred and twenty-four patients met the inclusion criteria and consented to participate in this study. There were 53 patients with excellent DASH score, 95 excellent VAS score and 51 excellent outcomes at mean follow-up of 75.5 months (Range: 5-402.8 months). Concomitant pathology and surgical management were less likely to have excellent DASH and VAS scores, while traumatic aetiology and smoking were less likely to have excellent VAS score. Age was not predictive of excellent DASH or VAS score. CONCLUSIONS: Surgical management of TFCC injuries were associated with worse outcomes than if they were left alone. Smoking cessation is a patient-modifiable risk factor that may help improve outcomes.

Functional outcomes of reverse total shoulder arthroplasty in Boileau class 1 and class 2 proximal humeral fracture sequelae: A meta-analysis and systematic review.

Background: Reverse total shoulder arthroplasty (RTSA) is an increasingly popular salvage treatment option for proximal humeral fracture (PHF) sequelae. This meta-analysis aimed to conduct a pooled analysis of functional outcomes of RTSA in PHF sequelae, with subgroup analysis comparing between intracapsular (Class 1) and extracapsular (Class 2) PHF sequelae. Methods: A multi-database search (PubMed, OVID, EMBASE) was performed according to PRISMA guidelines on 27th July 2020. Data from all published literature meeting inclusion criteria were extracted and analysed. Findings: Eleven studies were included, comprising 359 shoulders (167 Class 1 and 192 Class 2). The mean age was 68.2 years, and the mean time between injury and surgery was 49 months, (1-516 months). Constant score and forward flexion improved by 31.8 (95%CI: 30.5-33.1, p < 0.001) and 60o (95%CI: 58o-62o, p < 0.001) respectively between pre-operative and post-operative values for both groups. Constant scores were better in Class 1 patients (MD = 3.60, 95%CI: 1.0-6.2, p < 0.001) pre-operatively and post-operatively (MD = 7.4, 95%CI: 5.8-9.0, p < 0.001). Forward flexion was significantly better in Class 1 patients (MD = 13o, 95%CI: 7o-17o, p < 0.001) pre-operatively, but was slightly better in Class 2 patients post-operatively (MD = 7o, 95%CI: 4o-10o, p < 0.001). Overall complication rate was 16.8%. Conclusion: Salvage RTSA is effective for PHF sequelae, with multiple factors contributing to the high complication rate.

Mechanism of tacrine block at adult human muscle nicotinic acetylcholine receptors.

We used single-channel kinetic analysis to study the inhibitory effects of tacrine on human adult nicotinic receptors (nAChRs) transiently expressed in HEK 293 cells. Single channel recording from cell-attached patches revealed concentration- and voltage-dependent decreases in mean channel open probability produced by tacrine (IC(50) 4.6 microM at -70 mV, 1.6 microM at -150 mV). Two main effects of tacrine were apparent in the open- and closed-time distributions. First, the mean channel open time decreased with increasing tacrine concentration in a voltage-dependent manner, strongly suggesting that tacrine acts as an open-channel blocker. Second, tacrine produced a new class of closings whose duration increased with increasing tacrine concentration. Concentration dependence of closed-times is not predicted by sequential models of channel block, suggesting that tacrine blocks the nAChR by an unusual mechanism. To probe tacrine's mechanism of action we fitted a series of kinetic models to our data using maximum likelihood techniques. Models incorporating two tacrine binding sites in the open receptor channel gave dramatically improved fits to our data compared with the classic sequential model, which contains one site. Improved fits relative to the sequential model were also obtained with schemes incorporating a binding site in the closed channel, but only if it is assumed that the channel cannot gate with tacrine bound. Overall, the best description of our data was obtained with a model that combined two binding sites in the open channel with a single site in the closed state of the receptor.

Artificial ligament reconstruction of sternoclavicular joint instability: report of a novel surgical technique with early results.

Symptomatic instability of the sternoclavicular (SC) joint is an uncommon problem. The majority of patients respond well to nonoperative measures, although a small number require reconstructive surgery for symptomatic instability, with varying surgical techniques reported in the literature. We report a series of 5 operations (in 4 patients) with chronic SC joint instability treated by reconstruction of SC and costoclavicular ligaments using an artificial ligament weave (LARS: Ligament Augmentation and Reconstruction System). Preoperative and postoperative disabilities of the Arm, Shoulder, and Hand (DASH) Scores and Oxford Shoulder Scores were collected to evaluate the outcomes. The patients had a mean age of 20 years (range, 17 to 22 y), with 2 male and 2 female patients. Three of the patients had traumatic dislocation of the SCJ and 1 patient had bilateral symptomatic atraumatic instability. Anterior instability was observed in 4 joints and posterior instability in 1 joint. In all cases, reconstruction was achieved with a 30 mm LARS ligament. Postoperative follow-up was for an average of 29 months (range, 19 to 41 mo). The DASH Score improved from 51.7 points (range, 24.2 to 75.0) preoperatively to 13.7 points (range, 8.3 to 20.8) postoperatively. The Oxford Shoulder Scores improved from 20.6 preoperatively (range, 15 to 32) to 41.8 postoperatively (range, 39 to 47). All patients returned to full activity including competitive sports. In conclusion, stabilization of the SC joint using a LARS ligament with a weave technique is a feasible option for young, active patients with symptomatic SC joint instability after failure of nonoperative treatment.

Pain and stiffness in partial-thickness rotator cuff tears.

To evaluate the null hypothesis of no difference in degree of pain or stiffness between patients with partial- and full-thickness tears of the rotator cuff, we measured pain and stiffness in a cohort of consecutive patients who underwent arthroscopy for rotator cuff-related conditions. Pain was measured with a visual analogue scale, and range of motion was measured with a goniometer. Included in the study were 410 shoulders (410 patients), of which 214 had no tear, 66 had articular-sided partial-thickness tears, and 83 had single-tendon full-thickness tears. There was no statistical difference for measurements of pain or stiffness between patients with partial- and full-thickness tears, and hence the null hypothesis was upheld. Neither pain nor stiffness should be used as a diagnostic indicator for differentiation of partial- and full-thickness rotator cuff tears.

N-Hydroxy sulfonimidamides as new nitroxyl (HNO) donors.

Chlorination and condensation of simple sulfinamides with O-benzyl and O-tert-butyl dimethyl siloxy hydroxylamine gives O-protected N-hydroxy sulfonimidamides. Deprotection of these compounds produces the corresponding sulfinamide and nitrous oxide, which provides evidence for the intermediacy of nitroxyl (HNO) and identifies these compounds as new potential HNO donors.

Structural basis for epibatidine selectivity at desensitized nicotinic receptors.

The agonist binding sites of the fetal muscle nicotinic acetylcholine receptor are formed at the interfaces of alpha-subunits and neighboring gamma- and delta-subunits. When the receptor is in the nonconducting desensitized state, the alpha-gamma site binds the agonist epibatidine 200-fold more tightly than does the alpha-delta site. To determine the structural basis for this selectivity, we constructed gamma/delta-subunit chimeras, coexpressed them with complementary wild-type subunits in HEK 293 cells, and determined epibatidine affinity of the resulting complexes. The results reveal three determinants of epibatidine selectivity: gamma104-117/delta106-delta119, gamma164-171/delta166-177, and gammaPro190/deltaAla196. Point mutations reveal that three sequence differences within the gamma104-117/delta106-delta119 region are determinants of epibatidine selectivity: gammaLys104/deltaTyr106, gammaSer111/deltaTyr113, and gammaTyr117/deltaTyr119. In the delta-subunit, simultaneous mutation of these residues to their gamma equivalent produces high affinity, gamma-like epibatidine binding. However, converting gamma to delta affinity requires replacement of the gamma104-117 segment with delta sequence, suggesting interplay of residues in this region. The structural basis for epibatidine selectivity is explained by computational docking of epibatidine to a homology model of the alpha-gamma binding site.

Unilateral avulsion fracture of the transverse atlantal ligament: successful treatment in a rigid cervical collar.

A 34-year-old male sustained a unilateral avulsion fracture through the origin of the transverse atlantal ligament following a road traffic accident. This was successfully treated in a rigid neck collar for 8 weeks. Injuries to the transverse atlantal ligament are often associated with significant bony injury and atlanto-axial instability. Isolated injuries to the transverse ligament are extremely rare and the present case suggests that a trial of conservative management may be worth pursuing.