Minimally-invasive treatment of three- and four-part fractures of the proximal humerus in elderly patients

Surgical treatment of three and four-part proximal humeral fractures

Three- and four-part fractures of the proximal humerus are usually treated surgically. Open reduction with internal fixation (ORIF) is the method of choice in younger patients. Anatomic reduction of the tuberosities is crucial to ensure that, in the event of poorly tolerated avascular necrosis of the humeral head, hemiarthroplasty can be performed under optimal conditions. Suboptimal outcomes may occur after ORIF, as less-than-perfect reduction and fixation is poorly tolerated at the shoulder. Preoperative computed tomography must be performed routinely to analyse fragment displacement and comminution, classify the fracture, assess humeral head vitality, and evaluate the mechanical properties of the underlying bone. Fracture reduction relies on principles that are shared by the various available techniques. Reduction of each fragment should be assessed separately. Reduction of the humeral head to the shaft should be performed before reduction of the tuberosities. The fixation technique should ensure stability of the anatomic reduction, with secure fixation of the tuberosities and a minimal risk of material migration into the joint. Here, we provide a detailed discussion of the various techniques, with their advantages and drawbacks, to help surgeons select the method that is most appropriate to each individual patient.

Hemiarthroplasty for humeral four-part fractures for patients 65 years and older: a randomized controlled trial

BACKGROUND

Four-part fractures of the proximal humerus account for 3% of all humeral fractures and are regarded as the most difficult fractures to treat in the elderly. Various authors recommend nonoperative treatment or hemiarthroplasty, but the literature is unclear regarding which provides better quality of life and function.

QUESTIONS/PURPOSES

We therefore performed a randomized controlled trial to compare (1) function, (2) strength, and (3) pain and disability in patients 65 years and older with four-part humeral fractures treated either nonoperatively or with hemiarthroplasty.

METHODS

We randomly allocated 50 patients to one of the two approaches. There were no differences in patient demographics between the two groups. The Constant-Murley score was the primary outcome measure. Secondary outcome measures were the Simple Shoulder Test, abduction strength test as measured by a myometer, and VAS scores for pain and disability. All patients were assessed at 12 months.

RESULTS

We found no between-group differences in Constant-Murley and Simple Shoulder Test scores at 3- and 12-months followup. Abduction strength was better at 3 and 12 months in the nonoperatively treated group although the nonoperatively treated patients experienced more pain at 3 months; this difference could not be detected after 12 months.

CONCLUSIONS

We observed no clear benefits in treating patients 65 years or older with four-part fractures of the proximal humerus with either hemiarthroplasty or nonoperative treatment.

LEVEL OF EVIDENCE

Level I, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Modification of the Resch procedure

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.

Functional and radiographic medium-term outcome evaluation of the Humerus Block, a minimally invasive operative technique for proximal humeral fractures

BACKGROUND

Conservative treatment of severe displacement of proximal humeral fracture fragments yields bad functional results, but open operative techniques have a high risk of avascular necrosis of the humeral head. We performed a medium-term outcome evaluation of the Humerus Block (Synthes, Oberdorf, Switzerland), a minimally invasive technique used in selected patients with proximal humeral fractures, to investigate the functional and radiographic outcome.

MATERIALS AND METHODS

Of 47 patients operated on with the Humerus Block, 34 with a minimum follow-up of 30 months and a mean follow-up of 4 years and 4 months, were invited for interview, radiographic evaluation, and functional analysis by the Constant, Disabilities of Arm, Shoulder and Hand (DASH) and the University of California, Los Angeles (UCLA) scorings. Paired t test was used to investigate equivalence of the geometric mean scores of the trauma and control arm, for the scores of the functional analyses, and for the scores for mobility of the shoulder.

RESULTS

Scorings and clinical examination showed that 85% of shoulder function and motion were preserved compared with the control arm. Radiographic evaluation showed very good healing and positioning of the fracture fragments, and only 10% developed avascular necrosis of the humeral head.

CONCLUSIONS

With very satisfied patients; good clinical, functional, and radiographic outcomes; a short hospital stay; few complications; a reduced cost of implant; and a low incidence of avascular necrosis, this technique is a valuable alternative for operative treatment of proximal humeral fractures.

The Humerusblock NG: a new concept for stabilization of proximal humeral fractures and its biomechanical evaluation

BACKGROUND

The Humerusblock NG represents a new semi-rigid angular stable fixation device for minimally invasive stabilization of proximal humeral fractures. This study evaluates the function and stability of the Humerusblock NG and its biomechanical properties on the basis of two different fracture models under cyclic loading.

METHODS

Six fresh frozen human humeri were tested in a dynamic shoulder joint abduction motion test bench, simulating abduction between 15° and 45°. A stable wedge fracture with intact medial hinge and an unstable fracture with 5-mm gap were loaded for 500 cycles. Radiological measurement of implant migration was performed.

RESULTS

The stable fracture model showed a slow constant fracture settling. The unstable fracture model showed initial fracture settling with closure of the medial fracture gap during the first 20 cycles. Thereafter, a slow constant settling of the fracture was measured comparable to the stable fracture model. Maximum varus tilt was 3.17° for the stable and 3.68° for the unstable fracture pattern. Radiological analysis showed no change in the tip apex distance and a significant settling of the implants fixation pins in the unstable fracture model. None of the specimen failed during the testing.

CONCLUSION

The Humerusblock NG allows for angular stable dynamic fixation of two-part proximal humeral fractures. It enables closure of the fracture gap and maintains fracture compression during loading, a concept already established in the stabilization of femoral neck fractures (dynamic hip screw). Clinical trials will be necessary to evaluate the value of this device in daily practice.

LEVEL OF EVIDENCE

Basic science study.

Technique of Kirschner wire reduction and fixation of displaced two-part valgus angulated proximal humerus fractures at the surgical neck

This article describes the technique of closed reduction with percutaneous fixation using Kirschner wires in helping the reduction of two-part valgus angulated and displaced proximal humerus fractures at the surgical neck. Traditional open reduction may lead to more accurate anatomic reduction; however, extensive tissue dissection increases the risk of avascular necrosis. Thus, closed reduction of unstable fracture mostly required forceful reduction maneuvers, which can harm the vascular supply and increase hematoma formation. Reduction of the fractured sides can easily be performed by engaging Kirschner -wires with a joystick method and fixation can be secured by using threaded pins. Thirty-six consecutive patients with displaced, two-part, valgus-angulated proximal humerus fractures at the surgical neck were treated by this method. The patients were followed for an average of 38 months. All fractures healed. According to the Constant scoring system, 21 patients (58%) had excellent, 9 patients (25%) had good, and 6 patients (17%) had fair results. The technique of closed reduction with a joystick method and percutaneous fixation is regarded as a reasonable treatment alternative in displaced two-part valgus angulated proximal humerus fracture.

[Proximal humerus fracture: new aspects in epidemiology, fracture morphology, and diagnostics]

The incidence of proximal humerus fractures is rising and they constitute the third most frequent fracture in the elderly after femoral fractures in the hip area and radius fractures. They are caused by the age-related increase in osteoporosis. In contrast to young people, low-energy trauma involved in simple falls represents the mechanism that leads to the injury in older people. Numerous authors have introduced systems for the classification of proximal humerus fractures.After a thorough clinical examination of the affected extremity including assessment of circulation, motor function, and sensitivity, attention should be directed toward concomitant injuries, especially in the region of the shoulder girdle and thorax. Advocated imaging consists of anteroposterior and axial views of the affected shoulder. Disagreement over management of this fracture is quite considerable and treatment ranges from a conservative approach through to procedures for minimally invasive plate osteosynthesis, open fixed-angle locked plating, and nailing up to prosthetic replacement.

Minimally invasive polyaxial locking plate fixation of proximal humeral fractures: a prospective study

BACKGROUND

The surgical treatment for displaced humeral head fractures overlooks a broad variety of surgical techniques and implant systems. A standard operative procedure has not yet been established. In this article, we report our experience with a second-generation locking plate for the humeral head fracture that is applied in a standardized nine-step minimally invasive surgical technique (MIS).

METHODS

In a prospective study from May 2008 until November 2009, a cohort of 79 patients with 80 proximal humerus fractures were operated in a MIS procedure using a polyaxial locking plate. Follow-up examination at 6 weeks and 6 months postoperative included radiologic examinations and a clinical outcome analysis by the Constant Score, the Visual Analog Scale for pain, and the Daily Activity Score.

RESULTS

The mean patient age was 65.5 years ± 19 years. According to the Neer classification, there were 18 (22.5%) two-part (Neer III), 48 (60%) three-part (Neer IV), and 14 (17.5%) four-part fractures (Neer IV/V). The operation time averaged 65.6 minutes ± 27 minutes. In 13 patients (16.3%), revision was necessary because of procedure-related complications. After 6 months, the Visual Analog Scale for pain was 2.7 ± 1.6 and the Daily Activity Score showed 19.6 ± 6 points. The average age-related Constant Score after 6 months was 67.5 ± 24 points.

CONCLUSIONS

MIS surgery of displaced humeral head fractures can be performed in all types of humeral head fractures leading to low complication rates and good clinical outcome. A standardized stepwise procedure in fracture reduction and fixation is recommended to achieve reliable good results.

Surgical treatment with an angular stable plate for complex displaced proximal humeral fractures in elderly patients: a randomized controlled trial

OBJECTIVE

The objective of the study was to evaluate functional outcome, patient self-assessment, and radiographic outcome at 1 year in displaced three- and four-part proximal humeral fractures (OTA group 11-B2 and 11-C2).

DESIGN

Randomized controlled trial.

SETTING

Academic medical center.

PATIENTS/PARTICIPANTS

Fifty patients aged 60 years or older with displaced three- or four-part proximal humeral fractures and no previous shoulder injuries were randomized either to surgical treatment or to conservative closed treatment. Twenty-five patients were included in each group. Forty-eight patients completed 12-month follow-up. Two surgical patients died within 3 months.

INTERVENTION

The surgically treated group had a standardized surgical treatment with open reduction and internal fixation using an angular stable plate and cerclages. Instructed physical therapy started the third postoperative day. The conservative treatment group had a standardized nonoperative treatment that included closed reduction if displacement between the head and metaphyseal shaft fragment exceeded 50% of the diaphyseal diameter. Physical therapy started on the fifteenth postoperative day.

MAIN OUTCOME MEASUREMENTS

The main outcome was the mean difference in Constant score between the injured and noninjured shoulder at 12 months. The secondary outcomes were patient self-assessment (American Shoulder and Elbow Surgeons score) and radiographic ratings at 12 months.

RESULTS

At 12 months, mean Constant scores favored conservative treatment by 2.4 points (nonsignificant; P = 0.62). There was no significant difference in mean patient self-assessment. However, radiographic outcomes were significantly better for surgically treated patients.

CONCLUSION

There is no evidence of a difference in functional outcome at 1-year follow-up between surgical treatment and conservative treatment of displaced proximal humeral fractures in elderly patients.

Percutaneous pinning of three- or four-part fractures of the proximal humerus in elderly patients in poor general condition: MIROS® versus traditional pinning

PURPOSE

Elderly subjects often have fractures of the proximal humerus, which may be difficult to manage in patients in poor general condition. The MIROS is a new percutaneous pinning device allowing correction of angular displacement and stable fixation of fracture fragments. We evaluated the results of percutaneous fixation of three- or four-part fractures of the proximal humerus of patients in the American Society of Anesthesiologists physical status three or four treated either with MIROS or traditional percutaneous pinning (TPP).

METHODS

A total of 31 patients treated with MIROS and 27 undergoing TPP were enrolled in the study. Pre-operatively anteroposterior and transthoracic or axillary radiographs were obtained in all cases and computed tomography scans in patients with the most complex fractures. Follow-up evaluations were carried out at three, six, 12 and 16 weeks, and six months, one year and two years postoperatively, using the Constant Score (CS) and subjective shoulder value (SSV) methods.

RESULTS

Of the 58 patients, 52 could be evaluated at all follow-ups. In both three- or four-part fractures there were significantly higher CS and SSV scores in the MIROS compared to the TPP group at all the late follow-ups. Lower rates of deep infection, pin tract infection and pin mobilisation were found in the MIROS group (p < 0.001). In both groups there was a significant association between the final result (CS) and either the type of fracture or complications (p < 0.001).

CONCLUSIONS

The MIROS resulted in better clinical results and less complications than TPP in elderly patients. This method, however, may not be indicated for younger patients in good general condition.

Long term results of percutaneous fixation of proximal humerus fractures

BACKGROUND

Proximal humerus fracture in elderly osteoporotic patients usually leads to severe displaced and multifragmentary fractures. Associated comorbidities may limit surgical options and conservative treatment is commonly indicated, however, with variable results. In most cases, surgery is the treatment of choice in order to restore anatomical integrity, and allow early functional recovery. Several techniques were used over the years, each with specific indication. Percutaneous pinning after closed reduction, a mini-invasive technique and fixation by use of K-wires is not preferred commonly. We present our experience with this approach, focusing on its indications and advantages.

PATIENTS AND METHODS

A study group of 41 consecutive patients with a mean age of 65.5 years were evaluated clinically (VAS, Constant-Murley score, range of motion), and with radiological analysis: 35 patients finally completed a minimum followup of 24 months.

RESULTS

K-wires were removed after a mean interval of 4 weeks. Clinical and radiographic healing occurred in a mean time of 8.2 weeks in all fractures but one, with improvements in mean Constant-Murley score of 87.6 points, mean VAS of 2.3. In 33 patients, the reduction was considered satisfactory. In two cases, reduction was poor, but the patients however presented acceptable functional outcome.

CONCLUSIONS

Percutaneous pinning may represent a suitable option of treatment for 2-or 3-part proximal humerus fractures in selected subjects.

Proximal humeral fractures

Proximal humeral fractures may present with many different configurations in patients with varying co-morbities and expectations. As a result, the treating physician must understand the fracture pattern, the quality of the bone, other patient-related factors, and the expanding range of reconstructive options to achieve the best functional outcome and to minimize complications. Current treatment options range from non-operative treatment with physical therapy to fracture fixation using percutaneous or open techniques to arthroplasty reconstructions. This article reviews the current literature on the classification and treatment options for proximal humeral fractures, while seeking to help the reader to define the most appropriate treatment plan for each individual patient with this type of fracture.

Predicting failure after surgical fixation of proximal humerus fractures

BACKGROUND

Several studies reported high failures rates after internal fixation of proximal humerus fractures. Loss of reduction and screw cut-out are the most common reasons for revision surgery. Several risk factors for failure have been described in the literature. The aim of the present study was to assess risk factors for failure after surgical fixation of unstable proximal humerus fractures in a multivariate setup.

METHODS

Two different surgical techniques (PHILOS locking plate and Humerusblock) were used. In the PHILOS group, every kind of postoperative relative movement between the implant and the humeral head or shaft was defined as failure. In the Humerusblock group, postoperative movement between the humeral head and the shaft in terms of angulation or translational displacement was defined as failure. The following parameters were assessed: age, gender, cancellous bone mineral density (BMD) of the humeral head, fracture type, medial metaphyseal comminution, medial metaphyseal head extension, initial angulation of the humeral head in the frontal plane, initial anteversion of the humeral head, medial hinge displacement, maximum displacement of the tuberosities with respect to the head, surgical technique, anatomic reconstruction and restoration of the medial cortical support.

RESULTS

The following parameters were found to have a significant influence on the failure rate: age, local BMD, anatomic reduction, and restoration of the medial cortical support. The failure rate significantly increased with the number of risk factors.

CONCLUSION

Preoperative assessment of the local BMD and the patients' biological age as well as intraoperative anatomic reduction and restoration of the medial cortical support are the essentials for successful surgical fixation of proximal humerus fractures. Multifragmentary fracture patterns in old patients with low local BMD are prone for fixation failure. If the surgeon is not able to achieve anatomic reduction and restoration of the medial cortical support intraoperatively in this situation, adjustments such as augmentation or primary arthroplasty should be considered.

Modern perspectives of open reduction and plate fixation of proximal humerus fractures

Recent innovations have greatly increased the range of proximal humeral fractures that are amenable to open reduction and plate fixation.The optimum technique for some of the more complex fracture patterns is not yet fully refined.This article aims to describe the recent advances in the treatment of complex proximal humeral fractures by open reduction and locking plate fixation, focusing particularly on the indications for surgery, the operative techniques, and the expected outcomes after treatment.

Functional and quality-of-life results of displaced and nondisplaced proximal humeral fractures treated conservatively

OBJECTIVES

Functional and quality-of-life outcomes of conservatively treated proximal humeral fractures.

DESIGN

Prospective study.

SETTING

University orthopedic department at a hospital.

PATIENTS/PARTICIPANTS

Seventy consecutive patients between the ages of 60 and 85 years.

INTERVENTION

Conservative treatment.

MAIN OUTCOME MEASUREMENTS

Functional outcome measured according to the Constant score, quality of life assessed using EuroQol-5D, and fracture pattern analyzed with x-ray and computed tomography scan.

RESULTS

: All fractures consolidated uneventfully with no loss of reduction in either group. Four-part fractures obtained the worst functional results (33.66) followed by three-part fractures (54.64) and finally two-part fractures (65.88 and 71). Mild pain was expected in three- and four-part fractures, whereas two-part fractures achieved near complete pain relief. Nondisplaced fractures obtained a final Constant score of 73.58 and displaced fractures a score of 59.41 with significant differences in all Constant score items with the exception of external rotation. Although patients older than 75 years scored lower (54.63) than those younger than 75 years (70.83), there was no difference in the quality-of-life perception.

CONCLUSION

Conservative treatment of proximal humeral fractures in those patients older than age 75 years provides good pain relief with limited functional outcome. Despite limited functional outcome, this appears to have no effect on the quality-of-life perception in the population studied. Four-part fractures present the worst results and treatment options may need to be discussed with the patient to adjust treatment to patient expectations.

Reconstructive surgical treatment without bone grafting in nonunions of humeral surgical neck fractures

OBJECTIVE

To evaluate reconstruction surgery without bone grafting in humeral surgical neck nonunions using either a blade plate or the "Humerusblock" implant in small head fragments.

DESIGN

Retrospective cohort study, Evidence-Based Medicine Level IV.

SETTING

Paracelsus Medical University Salzburg, Department of Traumatology and Sports Injuries.

PATIENTS

Fifty-five patients (mean age, 66.2 years) with symptomatic nonunion after humeral surgical neck fractures were subjected to surgical reconstruction.

INTERVENTION

In 45 patients, open reduction and internal fixation using a blade plate was performed (Group 1). In 10 patients, the Humerusblock device was used (Group 2), because the head fragment of each of these patients was too small for plating. In no patients was bone grafting used.

MAIN OUTCOME MEASUREMENTS

Shoulder function, level of pain, and bone healing.

RESULTS

After a mean follow-up time of 74 months, the overall mean Constant score improved from 30.4% preoperatively to 83.2% postoperatively. The improvement was from 30.5% to 85.3% in Group 1 and from 32.2% to 75.4% in Group 2, which represented statistically significant improvements for both groups (P < 0.01). Radiologic bone healing was achieved in 51 patients (93%). The overall complication rate was high, 15%, and complications included plate loosening, avascular head necrosis, persistent nonunion, and infection.

CONCLUSIONS

Nonunion of humeral surgical neck fractures can be successfully treated by surgical reconstruction without bone grafting using either a blade plate or the Humerusblock for small head fragments. However, an increased complication rate is associated with this challenging posttraumatic pathology.

New trends in fixation of proximal humeral fractures: a review

Surgical treatment of proximal humeral fractures continues to be a challenge especially in osteoporotic patients. Locking plates and intramedullary nails have been used with satisfactory results but the previous reported complications have not been substantially reduced. Most of the existing studies involve a small number of patients followed up for a rather short period of time. Since proximal humeral fractures constitute a heterogenous group of complex fractures in an even more heterogenous population, no single fixation method is a panacea. Choice of implant and method of fixation should be selected according to individual patient and fracture pattern characteristics based on clearly defined indications and contraindications. Based on the findings of the existing clinical studies the authors propose a treatment algorithm.

The hybrid technique: potential reduction in complications related to pins mobilization in the treatment of proximal humeral fractures

BACKGROUND

Proximal humeral fracture fixation has a high incidence of complications especially when pins are used in elderly patients. In 2005, we introduced a new technique that augmented osteosutures by using 2.5-mm fully threaded pins and an external fixator (hybrid technique). The purpose of this study is to compare the outcomes of the hybrid technique (HT) with traditional pins fixation.

METHODS

A prospective nonrandomized study was organized on 2 consecutive series of patients: 51 patients treated with percutaneous fixation using 2.5-mm terminally threaded pins and 55 patients treated with the Hybrid technique. In both groups, an open reduction and osteosutures augmented with percutaneous fixation was used when closed reduction was insufficient to provide anatomical reduction. The patients were assessed at 6- and 12-month follows-ups using DASH score, Constant score, and Modified Constant score (MCS).

RESULTS

Sixteen patients treated with traditional pins experienced complications compared to 6 patients in the HT group (P = .006). The revision rate was 19% for the traditional pins group and 4% for the HT group (P = .04). Pins migration affected 8 patients in the traditional pins group and 1 case in the hybrid group (P = .01). The MCS at the 12-month follow-up was 89 ± 9 in the HT group and 77 ± 14 in the traditional pins group (P = .03). The MCS was negatively affected by complications and malreduction (P = .001).

CONCLUSION

The study suggests that the HT is a valuable option for the treatment of proximal humeral fractures. It has benefits compared to the traditional technique.

Elastic stabilisation of proximal humeral fractures with a new percutaneous angular stable fixation device (ButtonFix(®)): a preliminary report

INTRODUCTION

The ButtonFix(®) system represents a new angular stable percutaneous fixation device for stabilisation of fractures of the proximal humerus. The purpose of this study was to present a preliminary report of the radiological and clinical outcome after minimally invasive stabilisation of selected proximal humerus fractures with the ButtonFix(®).

PATIENTS AND METHODS

Seventeen patients with fractures of the proximal humerus were treated in our department with the ButtonFix(®) system. The mean final follow-up was performed 19 months postoperatively. Follow-up included assessment of postoperative reposition, range of motion, the DASH score, the Constant-Murley score, and the Short Form 36 (SF36).

RESULTS

Twelve patients showed anatomical head-to-shaft angles, four revealed minor valgus replacement, and one minor varus replacement. In one patient unplanned revision surgery was necessary due to early secondary fracture dislocation requiring ORIF with an angular stable form plate. Implant removal was performed after 6 weeks in all patients. At the final follow-up, mean range of motion was: flexion 135°, extension 45°, abduction 142°, internal rotation 51°, and external rotation 62°. The mean Constant-Murley score was 70. The mean DASH score was 26 points and the average SF36 score was 76 points. One patient showed radiological signs of avascular necrosis.

CONCLUSION

The ButtonFix(®) system represents a valuable tool in the treatment of proximal humeral fractures with results indicating fewer complications compared to prior percutaneous fixation devices. Moreover, the ButtonFix(®) seems to be able to maintain reduction even in elderly patients with potentially reduced bone mass.

Effect of proximal humeral fractures on the age-specific prevalence of rotator cuff tears

BACKGROUND

This study examined the effect of proximal humeral fractures on the age- and shoulder-specific prevalence of rotator cuff tears (RCTs) as well as the association with fracture severity, patient age, and clinical outcome.

METHODS

Sixty-three fractures were treated conservatively; in 114 cases, minimally invasive osteosynthesis, and in 125 cases, open reduction and plate fixation were performed without rotator cuff reconstruction. After 4.4 years, all 302 patients were clinically and sonographically examined.

RESULTS

We examined 139 two-part, 95 three-part, and 68 four-part fractures according to Neer and 134 A, 86 B, and 82 C fractures according to the AO classification. There were 52 patients (17%) with a complete rotator tear (RCT) only at the injured shoulder and 11 patients (4%) with a complete RCT only at the contralateral shoulder (p < 0.0001). Independent of the patient's age at follow-up, the prevalence of an RCT in the fractured shoulder was 13% higher than the prevalence in the opposite shoulder. Four-part fractures showed a significant association with a complete RCT (p = 0.047).Of 74 patients with a satisfactory or poor Constant Score, 33 (44.6%) had RCTs. In the remaining 228 patients with a good to excellent result, only 26 (11.4%) had RCTs. We showed that 66% of the RCTs observed at the fractured shoulder were caused by trauma. There was no association between treatment modality and a complete RCT.

CONCLUSION

RCTs may need special attention in initial diagnostics, management, and follow-up especially in severe proximal humeral fractures.

Closed reduction and minimally invasive percutaneous fixation of proximal humerus fractures using the Humerusblock

OBJECTIVE

To evaluate the results after closed reduction and percutaneous fixation of displaced fractures of the proximal humerus with the Humerusblock system.

DESIGN

Prospective case series.

SETTING

Level 1 trauma center.

PATIENTS AND METHODS

Fifty-eight consecutive patients with displaced proximal humerus fractures were followed over a mean period of 15.2 (12-28) months.

INTERVENTION

All patients were treated by closed reduction and percutaneous fixation using the Humerusblock.

MAIN OUTCOME MEASUREMENTS

Intra- and postoperative complications, secondary fracture displacement, rate of avascular necrosis, range of motion, pain according to a visual analogue scale, and the Constant-Murley shoulder score.

RESULTS

No intra-operative complications occurred. Implant removal was performed 6 to 8 weeks after the initial surgery. In 13 (22%) cases, secondary impaction of the humerus lead to perforation of k-wires through the articular surface requiring premature removal of the entire implant after an average time of 4.9 weeks. Five patients required revision surgery, including open reduction and fixation because of secondary fracture displacement. In five patients, k-wires loosened and backed out laterally, requiring revision surgery and retightening of the clamping screws in three cases and premature implant removal in two. Two patients showed radiologic signs of partial avascular necrosis at the final follow-up. The average range of motion of the operated shoulder was flexion 119.2 degrees, extension 33.5 degrees, internal rotation 64.2 degrees, external rotation 41.4 degrees. and abduction 107 degrees. The mean visual analogue scale pain score was 1.1 points, and the mean Constant-Murley score was 73.6 points, representing 88% of the mean Constant-Murley score of the unaffected shoulder.

CONCLUSION

The Humerusblock system allows reliable minimally invasive fixation of selected displaced proximal humerus fractures, even in elderly patients with potentially reduced bone mass. In this study, postoperative rates of avascular necrosis were lower than that which has been reported after conservative treatment and open anatomic reduction and internal fixation. The overall unplanned re-operation rate of 40% was high, comparable with what has been reported for conventional percutaneous pinning. However, clinical outcome was good in 77% of the patients, and reduction could be held in 91% successfully, including elderly patients with potentially reduced bone mass.

The medial periosteal hinge, a key structure in fractures of the proximal humerus: a biomechanical cadaver study of its mechanical properties

The medial periosteal hinge plays a key role in fractures of the head of the humerus, offering mechanical support during and after reduction and maintaining perfusion of the head by the vessels in the posteromedial periosteum. We have investigated the biomechanical properties of the medial periosteum in fractures of the proximal humerus using a standard model in 20 fresh-frozen cadaver specimens comparable in age, gender and bone mineral density. After creating the fracture, we displaced the humeral head medial or lateral to the shaft with controlled force until complete disruption of the posteromedial periosteum was recorded. As the quality of periosteum might be affected by age and bone quality, the results were correlated with the age and the local bone mineral density of the specimens measured with quantitative CT. Periosteal rupture started at a mean displacement of 2.96 mm (SD 2.92) with a mean load of 100.9 N (SD 47.1). The mean maximum load of 111.4 N (SD 42.5) was reached at a mean displacement of 4.9 mm (SD 4.2). The periosteum was completely ruptured at a mean displacement of 34.4 mm (SD 11.1). There was no significant difference in the mean distance to complete rupture for medial (mean 35.8 mm (SD 13.8)) or lateral (mean 33.0 mm (SD 8.2)) displacement (p = 0.589). The mean bone mineral density was 0.111 g/cm(3) (SD 0.035). A statistically significant but low correlation between bone mineral density and the maximum load uptake (r = 0.475, p = 0.034) was observed. This study showed that the posteromedial hinge is a mechanical structure capable of providing support for percutaneous reduction and stabilisation of a fracture by ligamentotaxis. Periosteal rupture started at a mean of about 3 mm and was completed by a mean displacement of just under 35 mm. The microvascular situation of the rupturing periosteum cannot be investigated with the current model.