Aims. This is a prospective randomised controlled trial comparing the functional outcomes of plate fixation and elastic stable intramedullary nailing (ESIN) of completely displaced mid-shaft fractures of the clavicle in the active adult population. Patients and Methods. We prospectively recruited 123 patients and randomised them to either plate fixation or ESIN. Patients completed the Quick Disabilities of the Arm, Shoulder and Hand (DASH) score at one to six weeks post-operatively. They were followed up at six weeks, three and six months and one year with radiographs, and their clinical outcome was assessed using both the DASH and the Constant Score. Results. Plate fixation provided a faster functional recovery during the first six months compared with ESIN, but there was no difference after one year. The duration of surgery was shorter for ESIN (mean 53.4 minutes, 22 to 120) than for plate fixation (mean 69.7 minutes, 35 to 106, p < 0.001). The recovery after ESIN was slower with increasing fracture comminution and with open reduction (p < 0.05). Conclusion. Both methods return the patients to their pre-injury functional levels, but plate fixation has a faster recovery period in comminuted fractures than ESIN. ESIN has a shorter operative time and lower infection and implant rates of failure when using 2.5 mm nails or wider, suggesting that this is the preferred method in mid-shaft fractures with no comminution, whereas plate fixation is the superior method in comminuted fractures. Cite this article: Bone Joint J 2017;99-B:1095–1101

This study describes the epidemiology and outcome of 637 proximal humeral fractures in 629 elderly (≥ 65 years old) patients. Most were either minimally displaced (n = 278, 44%) or two-part fractures (n = 250, 39%) that predominantly occurred in women (n = 525, 82%) after a simple fall (n = 604, 95%), who lived independently in their own home (n = 560, 88%), and one in ten sustained a concomitant fracture (n = 76, 11.9%). The rate of mortality at one year was 10%, with the only independent predictor of survival being whether the patient lived in their own home (p = 0.025). Many factors associated with the patient’s social independence significantly influenced the age and gender adjusted Constant score one year after the fracture. More than a quarter of the patients had a poor functional outcome, with those patients not living in their own home (p = 0.04), participating in recreational activities (p = 0.01), able to perform their own shopping (p < 0.001), or able to dress themselves (p = 0.02) being at a significantly increased risk of a poor outcome, which was independent of the severity of the fracture (p = 0.001). A poor functional outcome after a proximal humeral fracture is not independently influenced by age in the elderly, and factors associated with social independence are more predictive of outcome. Cite this article: Bone Joint J 2014;96-B:970–7

Aims. There is a lack of long-term data for minimally invasive acromioclavicular (AC) joint repair. Furthermore, it is not clear if good early clinical results can be maintained over time. The purpose of this study was to report long-term results of minimally invasive AC joint reconstruction (MINAR) and compare it to corresponding short-term data. Methods. We assessed patients with a follow-up of at least five years after minimally invasive flip-button repair for high-grade AC joint dislocation. The clinical outcome was evaluated using the Constant score and a questionnaire. Ultrasound determined the coracoclavicular (CC) distance. Results of the current follow-up were compared to the short-term results of the same cohort. Results. A total of 50 patients (three females, 47 males) were successfully followed up for a minimum of five years. The mean follow-up was 7.7 years (63 months to 132 months). The overall Constant score was 94.4 points (54 to 100) versus 97.7 points (83 to 100) for the contralateral side showing a significant difference for the operated shoulder (p = 0.013) The mean difference in the CC distance between the operated and the contralateral shoulder was 3.7 mm (0.2 to 7.8; p = 0.010). In total, 16% (n = 8) of patients showed recurrent instability. All these cases were performed within the first 16 months after introduction of this technique. A total of 84% (n = 42) of the patients were able to return to their previous occupations and sport activities. Comparison of short-term and long-term results revealed no significant difference for the Constant Score (p = 0.348) and the CC distance (p = 0.974). Conclusion. The clinical outcome of MINAR is good to excellent after long-term follow-up and no significant differences were found compared to short-term results. We therefore suggest this is a reliable technique for surgical treatment of high-grade AC joint dislocation. Cite this article: Bone Joint J 2020;102-B(7):918–924

Aims. Recent studies of nonoperatively treated displaced midshaft clavicular fractures have shown a high incidence of nonunion and unsatisfactory functional outcome. Some studies have shown superior functional results and higher rates of healing following operative treatment. The aim of this study was to compare the outcome in these patients after nonoperative management with those treated with fixation. Patients and Methods. In a multicentre, parallel randomized controlled trial, 146 adult patients with an acute displaced fracture of the midthird of the clavicle were randomized to either nonoperative treatment with a sling (71, 55 men and 16 women with a mean age of 39 years, 18 to 60) or fixation with a pre-contoured plate and locking screws (75, 64 men and 11 women with a mean age of 40 years, 18 to 60). Outcome was assessed using the Disabilities of the Arm, Shoulder and Hand (DASH) Score, the Constant Score, and radiographical evidence of union. Patients were followed for one year. Results. A total of 60 patients in the nonoperative group and 64 in the operative group completed one-year follow-up. At three months’ follow-up, both the median DASH (1.7 vs 8.3) and median Constant scores (97 vs 90) were significantly better in the operated group (both p = 0.02). After six months and one year, there was no difference in the median DASH or Constant scores. The rate of nonunion was lower in the operative group (2 vs 11 patients, p < 0.02). Nine patients in the nonoperative group underwent surgery for nonunion. The plate was subsequently removed in 16 patients (25%). One patient had a new fracture after removal of the plate and one underwent revision surgery for failure of fixation. Conclusion. Fixation of a displaced midshaft clavicular fracture using a pre-contoured plate and locking screws results in faster functional recovery and a higher rate of union compared with nonoperative management, but the function of the shoulder is equal after six months and at one year. Cite this article: Bone Joint J 2018;100-B:1385–91

Aims. To compare the functionality of adults with displaced mid-shaft clavicular fractures treated either operatively or nonoperatively and to compare the relative risk of nonunion and reoperation between the two groups. Methods. Based on specific eligibility criteria, 120 adults (median age 37.5 years (interquartile range (18 to 61)) and 84% males (n = 101)) diagnosed with an acute displaced mid-shaft fracture were recruited, and randomized to either the operative (n = 60) or nonoperative (n = 60) treatment group. This randomized controlled, partially blinded trial followed patients for 12 months following initial treatment. Functionality was assessed by the Constant score (CS) (assessor blinded to treatment) and Disability of the Arm, Shoulder and Hand (DASH) score. Clinical and radiological evaluation, and review of patient files for complications and reoperations, were added as secondary outcomes. Results. At 12 months, 87.5% of patients (n = 105) were available for analysis. The two groups were well balanced based on demographic and fracture-related characteristics. At six weeks of follow-up a significant difference in DASH score (p < 0.001) was found in favour of operative treatment. The functionality at 12 months of follow-up based on CS and DASH was excellent in both groups (CS > 90 points and DASH < 10 points) with no significant difference (p = 0.277 for DASH and p = 0.184 for CS) between the two groups. The risk of symptomatic nonunion was significantly higher in the nonoperative group (p = 0.014), with a relative risk of 9.47 (95% confidence interval (CI) 1.26 to 71.53) in this group compared to the operative group. The number-needed-to-treat to avoid one symptomatic nonunion was 6.2. Initial treatment and age were factors significantly associated with nonunion in a logistic analysis. There were 26% in both groups (n = 14 in operative group and n = 15 in nonoperative group) who required secondary surgery, with most indications in the nonoperative group mandatory due to nonunion compared to most relative indications in the operative group requiring intervention due to implant irritation. Conclusion. Superiority was not identified with either an all-operative or all-nonoperative approach. The functionality at short term (within six weeks) seems igreater following operative treatment but was not found at one year. The risk of nonunion is significantly higher with nonoperative treatment. However, an all-operative approach to lower the nonunion risk may result in unnecessary surgery and is not recommended. Cite this article: Bone Joint J 2021;103-B(4):762–768

Aims. In order to determine whether and for whom serial radiological evaluation is necessary in one-part proximal humerus fractures, we set out to describe the clinical history and predictors of secondary displacement in patients sustaining these injuries. Patients and Methods. Between January 2014 and April 2016, all patients with an isolated, nonoperatively treated one-part proximal humerus fracture were prospectively followed up. Clinical and radiological evaluation took place at less than two, six, 12, and 52 weeks. Fracture configuration, bone quality, and comminution were determined on the initial radiographs. Fracture healing, secondary displacement, and treatment changes were recorded during follow-up. Results. In 100 patients (59 female, 41 male; mean age 57 years), 91 of the fractures (91%) remained stable. In five of nine patients (55%) with secondary displacement, surgery was recommended. Comminution, present in 23 patients (23%), was identified as a predictor of secondary displacement (p < 0.001). Patients’ age, sex, fracture configuration, and bone quality were not associated with secondary displacement (p ≥ 0.438). Nonoperative treatment resulted in a mean absolute Constant score (CS) of 80 (49 to 98), relative CS of 101% (63% to 138%), median subjective shoulder value of 95% (interquartile range (IQR) 90% to 100%), and median EuroQol five-dimensional questionnaire score of 0.89 (IQR 0.80 to 1.00) with bone union in all cases at one-year follow-up. Conclusion. Radiological re-evaluation was only necessary in patients presenting with comminution and may be redundant for 77% of patients with one-part proximal humerus fractures. Nonoperative treatment of one-part proximal humerus fractures remains the mainstay of treatment with a low rate of secondary surgery, a high union rate, and good clinical results. Cite this article: Bone Joint J 2019;101-B:1307–1312

In Neer type II (Robinson type 3B) fractures of the distal clavicle the medial fragment is detached from the coracoclavicular ligaments and displaced upwards, whereas the lateral fragment, which is usually small, maintains its position. Several fixation techniques have been suggested to treat this fracture. The aim of this study was to assess the outcome of patients with type II distal clavicle fractures treated with coracoclavicular suture fixation using three loops of Ethibond. This prospective study included 14 patients with Neer type II fractures treated with open reduction and coracoclavicular fixation. Ethibond sutures were passed under the coracoid and around the clavicle (UCAC loop) without making any drill holes in the proximal or distal fragments. There were 11 men and three women with a mean age of 34.57 years (29 to 41). Patients were followed for a mean of 24.64 months (14 to 31) and evaluated radiologically and clinically using the Constant score. Fracture union was obtained in 13 patients at a mean of 18.23 weeks (13 to 23) and the mean Constant score was 96.07 (91 to 100). One patient developed an asymptomatic fibrous nonunion at one year. This study suggests that open reduction and internal fixation of unstable distal clavicle fractures using UCAC loops can provide rigid fixation and lead to bony union. This technique avoids using metal hardware, preserves the acromioclavicular joint and provides adequate stability with excellent results. Cite this article: Bone Joint J 2013;95-B:983–7

Secure fixation of displaced proximal fractures of the humerus is a challenging problem. A total of 32 patients with acutely displaced three- or four-part proximal fractures of the humerus were treated by open reduction and internal fixation using the proximal humeral internal locking system (PHILOS) plate. There were 23 women and nine men with a mean age of 59.9 years (18 to 87). Data were collected prospectively and the outcomes were assessed using the Constant score. The mean follow-up was for 11 months (3 to 24). In 31 patients (97%) the fracture united clinically and radiologically at a mean of 10 weeks (8 to 24). The mean Constant score at final review was 66.5 (30 to 92). There was no significant difference in outcome when comparing patients aged more than 60 years (18 patients) with those aged less than 60 years (14 patients) (t-test, p = 0.8443). There was one case each of nonunion, malunion and a broken screw in the elderly population. This plate provides an alternative method of fixation for fractures of the proximal humerus. It provides a stable fixation in young patients with good-quality bone sufficient to permit early mobilisation. Failure of the screws to maintain fixation in the elderly remains a problem

The surgical treatment of three- and four-part fractures of the proximal humerus in osteoporotic bone is difficult and there is no consensus as to which technique leads to the best outcome in elderly patients. Between 1998 and 2004 we treated 76 patients aged over 70 years with three- or four-part fractures by percutaneous reduction and internal fixation using the Humerusblock. A displacement of the tuberosity of > 5 mm and an angulation of > 30° of the head fragment were the indications for surgery. Of the patients 50 (51 fractures) were available for follow-up after a mean of 33.8 months (5.8 to 81). The absolute, age-related and side-related Constant scores were recorded. Of the 51 fractures, 46 (90.2%) healed primarily. Re-displacement of fragments or migration of Kirschner wires was seen in five cases. Necrosis of the humeral head developed in four patients. In three patients a secondary arthroplasty had to be performed, in two because of re-displacement and in one for necrosis of the head. There was one case of deep infection which required a further operation and one of delayed healing. The mean Constant score of the patients with a three-part fracture was 61.2 points (35 to 87) which was 84.9% of the score for the non-injured arm. In four-part fractures it was 49.5 points (18 to 87) or 68.5% of the score for the non-injured arm. The Humerusblock technique can provide a comfortable and mobile shoulder in elderly patients and is a satisfactory alternative to replacement and traditional techniques of internal fixation

Aims. The aim of this study was to evaluate the clinical and radiological outcomes of locking plate fixation, with and without an associated fibular strut allograft, for the treatment of displaced proximal humeral fractures in elderly osteoporotic patients. Patients and Methods. We undertook a retrospective comparison of two methods of fixation, using a locking plate without an associated fibular strut allograft (LP group) and with a fibular allograft (FA group) for the treatment of these fractures. The outcome was assessed for 52 patients in the LP group and 45 in the FA group, with a mean age of 74.3 years (52 to 89), at a mean follow-up of 14.2 months (12 to 19). The clinical results were evaluated using a visual analogue scale (VAS) score for pain, the Constant score, the American Shoulder and Elbow Surgeons (ASES) score, and the range of movement. Radiological results were evaluated using the neck-shaft angle (NSA) and humeral head height (HHH). Results. The mean forward elevation in the LP and FA groups was 125.3° (. sd. 21.4) and 148.9° (. sd. 19.8), respectively (p = 0.042), while other clinical factors showed no statistically significant differences between the groups. The changes in NSA and HHH immediately after the operation and at final follow-up were significantly better in the FA group than in the LP group (p = 0.015 and p = 0.021, respectively). Conclusion. For comminuted proximal humeral fractures in osteoporotic patients, locking plate fixation with a fibular strut allograft shows satisfactory short-term results with respect to humeral head support and maintenance of reduction, and may reduce the incidence of complications associated with fixation using a locking plate alone. Cite this article: Bone Joint J 2019;101-B:260–265

Controversy surrounds the management of displaced three- and four-part fractures of the proximal humerus. The percutaneous Resch technique of stabilisation involves minimal soft-tissue dissection and a reduced risk of stiffness and avascular necrosis. However, it requires a second operation to remove Kirschner wires and the humeral block. We describe a modification of this technique that dispenses with the need for this second operation and relies on a sequential pattern of screw placement. We report the outcome of 32 three- or four-part fractures of the proximal humerus treated in this way at a mean follow-up of 3.8 years (2 to 8)). There were 14 men and 18 women with a mean age of 56 years (28 to 83). At final follow-up the mean Oxford shoulder scores were 38 (31 to 44) and 39 (31 to 42), and the mean Constant scores were 79 (65 to 92) and 72 (70 to 80) for three- and four-part fractures, respectively. We further analysed the results in patients aged < 60 years with high-energy fractures and those aged ≥ 60 years with osteoporotic fractures. There were no cases of nonunion or avascular necrosis. The results were good and comparable to those previously reported for the Resch technique and other means of fixation for proximal humeral fractures. We would recommend this modification of the technique for the treatment of displaced three-part and four-part fractures in patients both younger and older than 60 years of age

We used an inverted shoulder arthroplasty in 43 consecutive patients with a mean age of 78 years (65 to 97) who had sustained a three- or four-part fracture of the upper humerus. All except two were reviewed with a mean follow-up of 22 months (6 to 58). The clinical outcome was satisfactory with a mean active anterior elevation of 97° (35° to 160°) and a mean active external rotation in abduction of 30° (0° to 80°). The mean Constant and the mean modified Constant scores were respectively 44 (16 to 69) and 66% (25% to 97%). Complications included three patients with reflex sympathetic dystrophy, five with neurological complications, most of which resolved, and one with an anterior dislocation. Radiography showed peri-prosthetic calcification in 36 patients (90%), displacement of the tuberosities in 19 (53%) and a scapular notch in ten (25%). Compared with conventional hemiarthroplasty, satisfactory mobility was obtained despite frequent migration of the tuberosities. However, long-term results are required before reverse shoulder arthroplasty can be recommended as a routine procedure in complex fractures of the upper humerus in the elderly

We treated 47 patients with a mean age of 57 years (22 to 88) who had a proximal humeral fracture in which there was a severe varus deformity, using a standard operative protocol of anatomical reduction, fixation with a locking plate and supplementation by structural allografts in unstable fractures. The functional and radiological outcomes were reviewed. At two years after operation the median Constant score was 86 points and the median Disabilities of the Arm, Shoulder and Hand score 17 points. Seven of the patients underwent further surgery, two for failure of fixation, three for dysfunction of the rotator cuff, and two for shoulder stiffness. The two cases of failure of fixation were attributable to violation of the operative protocol. In the 46 patients who retained their humeral head, all the fractures healed within the first year, with no sign of collapse or narrowing of the joint space. Longer follow-up will be required to confirm whether these initially satisfactory results are maintained

Untreated 3- and 4-part fractures of the proximal humerus have a poor functional outcome. Open operation increases the risk of avascular necrosis and percutaneous reduction and fixation may be preferable. We report 27 patients, 9 with 3-part and 18 with 4-part fractures, treated by percutaneous reduction and screw fixation. Thirteen of the 4-part fractures were of the valgus type with no significant lateral displacement of the articular segment, and five showed significant shift. Instruments were introduced into the fracture through small incisions so that the fragments could be manoeuvred under the control of an image intensifier, taking advantage of ligamentotaxis as far as possible. A good reduction was achieved in most cases. The average follow-up was 24 months (18 to 47). All the 3-part fractures showed good to very good functional results, with an average Constant score of 91% (84% to 100%), and no signs of avascular necrosis. Good radiological results were achieved in 4-part fractures when impacted in valgus except for one patient with partial avascular necrosis of the head. In those with lateral displacement of the head, revision to a prosthesis was required in one patient because of avascular necrosis and in another because of secondary redisplacement of the fracture. Avascular necrosis was seen in 11% of 4-part fractures. The average Constant score in patients with 4-part fractures who did not need further operation was 87% (75% to 100%)

Aims

The aims of this network meta-analysis (NMA) were to examine nonunion rates and functional outcomes following various operative and nonoperative treatments for displaced mid-shaft clavicle fractures.

The generally-accepted treatment for large, displaced fractures of the glenoid associated with traumatic anterior dislocation of the shoulder is operative repair. In this study, 14 consecutive patients with large (> 5 mm), displaced (> 2 mm) anteroinferior glenoid rim fractures were treated non-operatively if post-reduction radiographs showed a centred glenohumeral joint. After a mean follow-up of 5.6 years (2.8 to 8.4), the mean Constant score and subjective shoulder value were 98% (90% to 100%) and 97% (90% to 100%), respectively. There were no redislocations or subluxations, and the apprehension test was negative. All fragments healed with an average intra-articular step of 3.0 mm (0.5 to 11). No patient had symptoms of osteoarthritis, which was mild in two shoulders and moderate in one. Traumatic anterior dislocation of the shoulder, associated with a large displaced glenoid rim fracture can be successfully treated non-operatively, providing the glenohumeral joint is concentrically reduced on the anteroposterior radiograph

We describe the results after open reduction and internal fixation of 22 consecutive displaced fractures of the glenoid with a mean follow-up of ten years. A posterior approach was used in 16 patients and an anterior in six, the approach being chosen according to the Ideberg classification of the fractures. The fixation failed in two patients, one of whom required a further operation. There were two cases of deep infection. At follow-up the median Constant score was 94% (mean 79%, range 17 to 100). The score was less than 50% in four patients, including the two who became infected. A further two had an associated complete palsy of the brachial plexus

The aim of this retrospective study was to review a series of patients with ipsilateral fractures of the neck of the scapula and of the clavicle. Between 1991 and 1996 a total of 79 general and orthopaedic surgeons treated 46 patients with a floating shoulder in The Netherlands. The records and radiographs of these patients were studied. Of the 35 patients available for follow-up, 31 had initially been treated conservatively and four by operation; three underwent secondary reconstructive surgery. The mean Constant score for the 28 patients treated conservatively was 76 and for the seven treated operatively it was 71 at a mean follow-up of 35 months. In six of the 28 patients treated conservatively the glenoid was dislocated caudally at the end of treatment; they had a score of 42. In the 22 patients without this dislocation the score was 85. We conclude that this rare injury is not inherently unstable and, in the absence of caudal dislocation of the glenoid, conservative treatment gives a good functional outcome

In 42 elderly patients, 33 women and nine men with a mean age of 72 years, we treated displaced fractures of the proximal humerus (34 three-part, 8 four-part) using a blade plate and a standard deltopectoral approach. Functional treatment was started immediately after surgery. We reviewed 41 patients at one year and 38 at final follow-up at 3.4 years (2.4 to 4.5). At the final review, all the fractures had healed. The clinical results were graded as excellent in 13 patients, good in 17, fair in seven, and poor in one. The median Constant score was 73 ± 18. Avascular necrosis of the humeral head occurred in two patients (5%). We conclude that rigid fixation of displaced fractures of the proximal humerus with a blade plate in the elderly patient provides sufficient primary stability to allow early functional treatment. The incidence of avascular necrosis and nonunion was low. Restoration of the anatomy and biomechanics may contribute to a good functional outcome when compared with alternative methods of fixation or conservative treatment. Regardless of the age of the patients, we advocate primary open reduction and rigid internal fixation of three- and four-part fractures of the proximal humerus

Aims

The aim of this study was to explore whether time to surgery affects functional outcome in displaced proximal humeral fractures

Objectives

The PROximal Fracture of the Humerus: Evaluation by Randomisation (PROFHER) trial has recently demonstrated that surgery is non-superior to non-operative treatment in the management of displaced proximal humeral fractures. The objective of this study was to assess current surgical practice in the context of the PROFHER trial in terms of patient demographics, injury characteristics and the nature of the surgical treatment.

Aims

This study identifies early risk factors for symptomatic nonunion of displaced midshaft fractures of the clavicle that aid identification of an at risk group who may benefit from surgery.

Both conservative and operative forms of treatment have been recommended for patients with a ‘floating shoulder’. We compared the results of conservative and operative treatment in 25 patients with this injury and investigated the use of the glenopolar angle (GPA) as an indicator of the functional outcome. A total of 13 patients (ten male and three female; mean age 32.5 years (24.7 to 40.4)) were treated conservatively and 12 patients (ten male and two female; mean age 33.67 years (24.6 to 42.7)) were treated operatively by fixation of the clavicular fracture alone. Outcome was assessed using the Herscovici score, which was also related to changes in the GPA at one year post-operatively.

The mean Herscovici score was significantly better three months and two years after the injury in the operative group (p < 0.001 and p = 0.003, respectively). There was a negative correlation between the change in GPA and the Herscovici score at two years follow-up in both the conservative and operative groups, but neither were statistically significant (r = -0.295 and r = -0.19, respectively). There was a significant difference between the pre- and post-operative GPA in the operative group (p = 0.017).

When compared with conservative treatment, fixation of the clavicle alone gives better results in the treatment of patients with a floating shoulder. The GPA changes significantly with fixation of clavicle alone but there is no significant correlation between the pre-injury GPA and the final clinical outcome in these patients.

Cite this article: Bone Joint J 2013;95-B:815–19.

We retrospectively analysed the clinical results of 30 patients with injuries of the sternoclavicular joint at a minimum of 12 months’ follow-up. A closed reduction was attempted in 14 cases. It was successful in only five of ten dislocations, and failed in all four epiphyseal disruptions. A total of 25 patients underwent surgical reduction, in 18 cases in conjunction with a stabilisation procedure.

At a mean follow-up of 60 months, four patients were lost to follow-up. The functional results in the remainder were satisfactory, and 18 patients were able to resume their usual sports activity at the same level. There was no statistically significant difference between epiphyseal disruption and sternoclavicular dislocation (p > 0.05), but the functional scores (Simple Shoulder Test, Disability of Arm, Shoulder, Hand, and Constant scores) were better when an associated stabilisation procedure had been performed rather than reduction alone (p = 0.05, p = 0.04 and p = 0.07, respectively).

We recommend meticulous pre-operative clinical assessment with CT scans. In sternoclavicular dislocation managed within the first 48 hours and with no sign of mediastinal complication, a closed reduction can be attempted, although this was unsuccessful in half of our cases. A control CT scan is mandatory. In all other cases, and particularly if epiphyseal disruption is suspected, we recommend open reduction with a stabilisation procedure by costaclavicular cerclage or tenodesis. The use of a Kirschner wire should be avoided.