AC joint osteoarthritis: The role of genetics. An MRI evaluation of asymptomatic elderly twins.

PURPOSE: The anatomy of the articular surfaces has historically identified as major responsible for acromioclavicular joint osteoarthritis (ACJO). On the other side, the almost 100% prevalence of ACJO in subjects over 50 years old seems to suggest a multifactorial etiology. We compared ACJO between asymptomatic elderly monozygotic (MZ) and dizygotic (DZ) twins to investigate the influence of genetics and environmental factors. MATERIALS AND METHODS: Thirty pairs of twins [15MZ-15DZ; mean age (SD): 63.70 (3.31); range: 53-72] were retrospectively enrolled. ACJO was evaluated on MRI through a 4-grade severity scale and ACJ configuration was assessed. Information regarding work activity were obtained. Heritability index was calculated. RESULTS: The intraclass correlation coefficient (ICC) value of 0.868 (95% CI; 0.798 to 0.917). An ICC values of 0.889 (95% CI; 0.798 to 0.944) and 0.843 (95% CI, 0.712 to 0.920) were found in the MZ and DZ groups, respectively. The polychoric correlation was 0.857 in the MZ twins and 0.757 in the DZ twins. The calculated heritability index was 0.20 (20%), and the contribution of the shared environment (c2) and unique environment (e2) was 0.66 (66%) and 0.14 (14%), respectively. No relationship between job types and ACJO in both the total cohort (r = 0.089; p = 0.499) and in the monozygotic (r = 0.247; p = 0.187) and the dizygotic twin groups (r = -0.084; p = 0.658) was found. CONCLUSIONS: The role of genetics on ACJO accounts for only 20%; a specific anatomical configuration of the articular surfaces only partially acts on the development of joint osteoarthritis. Environmental factors have the greatest impact. LEVEL OF EVIDENCE: IV.

Cartilage thickness of distal humerus and its relationships with bone dimensions: magnetic resonance imaging bilateral study in healthy elbows.

BACKGROUND: Little is known about the cartilage thickness of the distal humerus and how it affects the shape of the articular surface. Our aims were to assess cartilage thickness and to determine the extent to which it affects the true profile of the distal humerus. METHODS: We assessed 78 healthy elbows (39 subjects, 19 women and 20 men) with a mean age of 28 years (range, 21-32 years). Cartilage thickness was measured by use of high-definition magnetic resonance imaging scans at 19 different points of the articular surface, 13 on the trochlea and 6 on the capitellum, on the axial and coronal views. Bone diameters at the medial and lateral trochlear ridges, trochlear groove, and capitellum, as well as the articular surface width, were measured. Subject height was used as an indirect measurement of humerus length. Pearson correlation coefficients and the Student t test were used. RESULTS: Cartilage thickness showed a significant variation (range, 0.4-1.8 mm) independent of sex and side. It appeared thinner at the medial and lateral edges, whereas it increased at the level of the trochleocapitellar and trochlear grooves, the lateral trochlear ridges, and the center of the capitellum. The mean bone diameters of the medial ridge, lateral ridge, trochlear groove, and capitellum measured 25.1 mm, 21 mm, 16.9 mm, and 19.6 mm, respectively. The mean width of the articular surface was 42.9 mm (range, 35.8-50.2 mm). No significant correlation was found between cartilage thickness and bone dimensions. CONCLUSION: Cartilage thickness is not uniform and modifies the morphologic shape and diameters of the humeral articular surface. These findings may be relevant to anatomic prosthesis design.

Estimation of polycyclic aromatic hydrocarbon variability in air using high volume, film, and vegetation as samplers.

Organic films and leaves provide a medium into which organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs), can accumulate, resulting in a useful passive air sampler. In the present work, the temporal variability (weekly) in PAH concentrations and the fingerprint of films developed on window surfaces were investigated. Moreover, films and leaves of two tree species (Acer pseudoplatanus and Cornus mas) collected at the same time were used to derive PAH air concentrations and investigate their short-term variability. In general, the most abundant chemicals found in films were phenanthrene and pyrene (22%), followed by perylene (21%) and fluoranthene (16%), but the fingerprint (in contrast to leaves and air) changed over time. Leaf derived air concentrations were within a factor of 2 to 9 from measured values, while air concentrations back-calculated from films were within a factor of 2 to 53. This happened because predicted air concentrations using films and vegetation samplers (especially for low KOA chemicals) generally reflect only the last few hours (due to the fast equilibrium) of the weekly integrated samples obtained employing the high-volume sampler. This means that films and leaves can be usefully employed for predicting the short-term variability of low KOA organic contaminant air concentrations.

Discovery elbow system: 2- to 5-year results in distal humerus fractures and posttraumatic conditions: a prospective study on 24 patients.

PURPOSE: To prospectively evaluate preliminary results of the Discovery Elbow System (DES) used for acute distal humerus fractures and posttraumatic conditions. METHODS: We analyzed 24 patients (9 men and 15 women), with a mean age of 69 years (range, 45-89 y). Ten had comminuted distal humerus fractures (group I), and 14 had severe post-traumatic arthritis, chronic instability, or nonunion (group II). Clinical and radiographic evaluations were performed. The preoperative (group II) and postoperative (both groups) evaluations were assessed with the Mayo Elbow Performance Score and Mayo Elbow Performance Index, the Quick Disabilities of the Arm, Shoulder, and Hand score, and the modified American Shoulder and Elbow Surgeons score. Patient satisfaction was evaluated on a 4-point scale. RESULTS: Mean follow-up was 41 months (range, 29-63 mo). At the last evaluation, average flexion, extension, pronation, and supination were 136°, 17°, 80°, and 83°, respectively. The average Mayo Elbow Performance Score, Quick Disabilities of the Arm, Shoulder, and Hand score, and the modified American Shoulder and Elbow Surgeons score were 96, 20, and 84, respectively, and without significant intergroup differences. According to the Mayo Elbow Performance Index, there were 20 excellent, 3 good, and 1 fair result. Twenty patients were very satisfied or satisfied with the outcome. A significant increase in the functional scores was observed in group II compared with preoperative results. Radiological evaluation showed 1 patient with progressive radiolucency and 1 with a nonprogressive radiolucency at the final follow-up. No mechanical failures were observed. Two transient ulnar neuropathies, 1 wound infection, and 1 epicondyle fracture were observed. CONCLUSIONS: The DES yielded promising 2- to 5-year results in the treatment of acute fractures and posttraumatic conditions regarding pain relief, functional improvement, and patient satisfaction, achieving excellent results in most cases. The DES may represent an effective linked-implant option for total elbow replacement in such patients. However, long-term studies are needed. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Clinical usefulness of proximal ulnar and radial fracture-dislocation comprehensive classification system (PURCCS): prospective study of 39 cases.

BACKGROUND: Complex fracture-dislocations of the proximal ulna and radius represent a challenge even for expert orthopaedic surgeons. A new comprehensive classification, the proximal ulnar and radial fracture-dislocation comprehensive classification system (PURCCS), was recently proposed. The aim of this study was to analyze the clinical usefulness of this classification in a large series of patients. MATERIALS AND METHODS: We studied 38 patients (39 elbows) with a mean age of 56 years. All patients were classified with the PURCCS by use of standard radiography, computed tomography, and intraoperative fluoroscopy. Surgical treatment was performed according to the PURCCS therapeutic algorithm. Patients were followed up for a mean of 23 months. The clinical evaluation was performed with the Mayo Elbow Performance Score and Index (MEPS and MEPI); the Disabilities of the Arm, Shoulder, and Hand (DASH) score; and the modified American Shoulder and Elbow Surgeons (m-ASES) score. RESULTS: Each pattern of fracture-dislocation in our series finds its position within the PURCCS. At the last follow-up, the mean MEPS, DASH score, and m-ASES score were 91.2, 14.9, and 83.9, respectively. The mean extension, flexion, pronation, and supination were 19°, 136°, 81°, and 79°, respectively. According to the MEPI, 72%, 20%, and 8% of cases were rated excellent, good, and fair, respectively. Two patients with elbow stiffness underwent a reoperation, with final satisfactory results. CONCLUSION: The PURCCS helps identify the main lesions of each injury pattern; the associated therapeutic algorithm helps select correct surgical strategies. This study showed that the clinical results were satisfactory in the majority of cases, with few major complications and reinterventions. The PURCCS is a comprehensive classification that may contribute to the surgical management of these difficult fracture-dislocations. LEVEL OF EVIDENCE: Level IV, case series, treatment study.

Does shape and size of the stems affect the stress-shielding around press-fit radial head arthroplasty?

AIMS: It has been hypothesized that proximal radial neck resorption (PRNR) following press-fit radial head arthroplasty (RHA) is due to stress-shielding. We compared two different press-fit stems by means of radiographs to investigate whether the shape and size of the stems are correlated with the degree of PRNR. METHODS: The radiographs of 52 RHAs were analyzed both at 14 days postoperatively and after two years. A cylindrical stem and a conical stem were implanted in 22 patients (group 1) and 30 patients (group 2), respectively. The PRNR was measured in the four quadrants of the radial neck and the degree of stem filling was calculated by analyzing the ratio between the prosthetic stem diameter (PSD) and the medullary canal diameter (MCD) at the proximal portion of the stem (level A), halfway along the stem length (level B), and distally at the stem tip (level C). RESULTS: Overall, 50 of the 52 patients displayed PRNR. The mean PRNR observed was 3.9 mm (0 to 7.4). The degree of endomedullary stem filling at levels A, B, and C was 96%, 90%, and 68% in group 1, and 96%, 72%, and 57%, in group 2, with differences being significant at levels B (p < 0.001) and C (p < 0.001). No significant correlations emerged between the severity of PRNR and the three stem/canal ratios either within each group or between the groups. CONCLUSION: PRNR in press-fit RHA appears to be independent of the shape and size of the stems. Other causes besides stem design should be investigated to explain completely this phenomenon. Cite this article: Bone Joint J 2021;103-B(3):530-535.

Terrible triad of the elbow: is it still a troublesome injury?

BACKGROUND: Terrible triad injury (TTI), one of the main patterns of complex elbow instability, is difficult to treat and yields conflicting surgical results. We analyzed prospectively a series of patient affected by TTI and treated according to the current diagnostic and surgical protocols to investigate whether their application allow to obtain more predictable outcomes. MATERIAL AND METHODS: We analyzed 26 patients with a mean age of 52 years. Preoperative X-rays and CT were performed; all patients were operated by the same elbow surgeon and underwent the same surgical and rehabilitation treatment. Final functional outcome was assessed by the Mayo Elbow Performance Score (MEPS), Quick-Disability of the Arm Shoulder and Hand-score (Q-DASH) and the modified-American Shoulder and Elbow Surgeons score (m-Ases). A radiographic evaluation was also performed. RESULTS: Mean follow-up was 31 months. At final evaluation, mean flexion, extension, supination and pronation were 137°, 10°, 77° and 79°, respectively; mean MEPS, m-ASES and Q-DASH scores were respectively 96, 91 and 8 points. Complications observed after first surgery were: elbow stiffness in 5 cases, mild posterolateral instability in 3 cases, chronic subluxation in 1 case. Radiographic evaluation showed secondary arthritis in 9 cases, symptomatic HO in 3 cases and late hardware displacement in 2 cases. Six out of 26 patient underwent reoperation with final satisfactory results. CONCLUSION: The current diagnostic and therapeutic protocols allow obtaining satisfactory clinical outcomes in majority of cases but a high number of major and minor unpredictable complications persist yet. In this series, low compliance, obesity, and extensive soft elbow tissue damage caused by high-energy trauma represented negative prognostic factors unrelated to surgery. On the other hand, the strict application of current algorithms by an expert elbow surgeon appears to improve clinical results by reducing the influence of other avoidable negative prognostic factors well known in current literature, such as the incomplete recognition of injuries, delayed treatment, inadequate treatment of bony and ligamentous injuries, prolonged immobilization and, last but not least, the surgeon's inexperience. LEVEL OF EVIDENCE: Level IV, Case series, Treatment study.

Towards more ecologically realistic scenarios of plant uptake modelling for chemicals: PAHs in a small forest.

The importance of plants in the accumulation of organic contaminants from air and soil was recognized to the point that even regulatory predictive approaches now include a vegetation compartment or sub-compartment. However, it has recently been shown that many of such approaches lack ecological realism to properly evaluate the dynamic of air/plant/soil exchange, especially when environmental conditions are subject to sudden variations of meteorological or ecological parameters. This paper focuses on the development of a fully dynamic scenario in which the variability of concentrations of selected chemicals in air and plant leaves was studied weekly and related to the corresponding meteorological and ecological parameters, to the evaluate their influence. To develop scenarios for modelling purposes, two different sampling campaigns were performed to measure temporal variability of: 1) polycyclic aromatic hydrocarbon (PAH) concentrations in air of a clearing and a forest site, as well as in leaves of two broadleaf species and 2) two important leaf and canopy traits, specific leaf area (SLA) and leaf area index (LAI). The aim was to evaluate in detail how the variability of meteorological and ecological parameters (SLA and LAI) can influence the uptake/release of organic contaminants by plants and therefore air concentrations. A principal component analysis demonstrated how both meteorological and ecological parameters jointly influence PAH air concentrations. SLA, LAI, as well as leaf density were showed to change over time and among species and to be directly proportional to leaf/canopy uptake rate. While hazelnut had the higher leaf uptake rate, maple became the most important species when considering the canopy uptake rate due to its higher LAI. Other species specific traits, such as the seasonal variation in production of new leaves and the timing of bud burst, were also shown to influence the uptake rate of PAHs by vegetation.

Change in quality of life and cost/utility analysis in open stage-related surgical treatment of elbow stiffness.

The goals of this study were to examine the improvement in quality of life achieved after open surgical treatment of elbow stiffness and to verify the cost/utility ratio of surgery. Thirty-three patients (22 men and 11 women) underwent surgery. The etiologies of elbow stiffness were posttraumatic conditions (n=26), primary osteoarthritis (n=5), and rheumatoid arthritis (n=2). Surgery included 14 ulnohumeral arthroplasties, 6 ulnohumeral arthroplasties associated with radiocapitellar replacement, 5 ulnohumeral arthroplasties associated with radial head replacement, and 8 total elbow arthroplasties. All patients were evaluated pre- and postoperatively with the Mayo Elbow Performance Score, the Mayo Elbow Performance Index, the modified American Shoulder and Elbow Surgeons score, the Quick Disabilities of the Arm, Shoulder and Hand score, and the Short Form 36 after a mean follow-up of 26 months. Possible variables affecting clinical outcome and quality of life improvement were assessed. The cost/utility ratio was evaluated as diagnosis-related group reimbursement per quality-adjusted life year. Mayo Elbow Performance Scores and modified American Shoulder and Elbow Surgeons scores increased, on average, by 43 and 41 points, respectively (P<.0001). Quick Disabilities of the Arm, Shoulder and Hand scores decreased, on average, by 44 points (P<.0001). The improvement in the SF-36 physical and mental component summary score was 7.6 and 7, respectively (P=.0001 and .0018). The cost/utility ratio ranged between 670 and 817 Euro/quality-adjusted life year. A significant correlation was found between pain score and quality of life improvement. An inverse correlation emerged between pre- and postoperative quality of life score. The current study shows that open surgery significantly improves quality of life and elbow function. Selecting the surgical procedure that most effectively reduces pain appears to be the most relevant variable responsible for quality of life improvement. Surgery shows a satisfactory cost/utility ratio, justifying a health spending increase to reduce the social costs resulting from lingering elbow stiffness.

Soft tissue constraint injuries in complex elbow instability: surgical techniques and clinical outcomes.

The surgical procedures for and outcomes of soft tissue constraint reconstruction in complex elbow instability have been rarely investigated. The purpose of this study was to analyze the clinical outcomes in a series of patients with complex elbow instability in whom the associated soft tissue constraint injures were identified and treated based on the pathoanatomic changes found intraoperatively. Forty-five patients (23 men and 22 women; mean age, 54 years) with complex elbow instability were followed prospectively. Surgical treatment included the anatomic reduction and internal fixation of any fracture and radial head replacement in Mason type III injuries. Soft tissue constraint lesions were then repaired based on the type of lesion (eg, proximal or distal ligament avulsion, middle-zone lesion, or presence of detached bony fragments). Posterolateral capsular lesions and common extensor and flexor origin injuries were also repaired. Patients were followed clinically and radiographically after a mean of 25 months. Functional range of motion was achieved in 39 (86%) patients. Average Mayo Elbow Performance Score; Disabilities of the Arm, Shoulder and Hand score; and American Shoulder and Elbow Surgeons shoulder score were 94, 5.6, and 89, respectively. At last follow-up, 42 (93%) patients showed no evidence of elbow instability, 2 (4%) patients had mild varus instability, and 1 (2%) patient had moderate posterolateral instability. The accurate identification of pathoanatomic changes of elbow soft tissue constraint lesions associated with complex elbow instability is an essential prerequisite to planning proper surgical treatment. The results of this study show that, in patients with complex elbow instability, once the fracture has been treated and each type of soft tissue constraint lesion adequately repaired, a high percentage of satisfactory functional outcomes may be achieved.

Soft tissue constraint injuries in complex elbow instability: prevalence, pathoanatomy, and classification.

The types and prevalence of soft tissue constraint injuries associated with complex elbow instability have been rarely investigated. The purpose of this study was to analyze the intraoperative findings of soft tissue constraint injuries in complex elbow instability and provide a comprehensive classification of these lesions. Forty-seven patients undergoing surgery for complex elbow instability were prospectively analyzed. Ligament injuries were classified as simple or complex lesions, depending on whether the ligament was damaged at a single zone or 2 to 3 zones, including its proximal, middle, and distal portions. Posterolateral capsule injuries were classified as small or large in the presence of capsular avulsions smaller than or larger than 1 cm, respectively. The presence of lesions of the common extensor and flexor-pronator muscles were also recorded. Ligament injuries were found in 96% of patients. The lateral collateral ligament showed a simple lesion, including a proximal and distal avulsion, in 19% and 2% of patients, respectively, and a middle-zone tear in 13%. Complex lesions, including the association of a middle-zone tear with a proximal or distal avulsion, were found in 47% and 6% of patients, respectively, and a combination of proximal, distal, and middle-zone injuries in 4%. Small and large posterolateral capsule lesions were found in 49% and 17% of patients, respectively. A medial collateral ligament injury was present in 45% of patients. A high prevalence of soft tissue constraint lesions was found to be associated with complex elbow instability. Soft tissue constraint status should be carefully evaluated pre- and intraoperatively in patients with complex elbow instability. The classification reported herein may be helpful in planning the proper treatment of these complex injuries.