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

Does minimally invasive external fixation of proximal humerus fractures provide adequate stability? A biomechanical in vitro study

INTRODUCTION

Proximal humerus fractures are usually treated with rigid angle-stable plates or nails. As an alternative, semi-rigid, minimally invasive systems have been developed for supportive fixation. A new system uses this principle with 2.5 mm partially threaded pins and external fixation.

AIM

This study aimed to compare the fracture stability of the fixator with an angular stable plate about whether the mechanical stability is sufficient for early postoperative mobilisation.

MATERIALS AND METHODS

Human proximal humeri (paired, female, age ≥ 60, n = 8) were cut to a 3-part fracture and treated with an external fixator (Galaxy Shoulder, Orthofix) or an angular stable plate (Philos, DePuy Synthes). A physiological load was simulated in vitro based on a 45° abduction motion. The load level was continuously increased from 10 to 320 N within 10,000 cycles simulating the loads during rehabilitation. This was followed by another 10,000 cycles at 320 N for fatigue testing. Fracture motion was recorded with a 3D camera. Fracture stability was evaluated at a partial load of 160 N and 240 N (simulating loads during early mobilisation).

RESULTS

The fracture motion at the lateral aspect was significantly (p < 0.034) larger for the fixator compared to the plate both for axial and for shear movements, while at the medial aspects fracture motions were similar. Both fixation systems adequately stabilized the lateral tubercle fragment with no significant differences between fixation techniques. The migration of the fixator pins (1.1 ± 1.0 mm) and valgus rotation of the head fragment were minimal (3.1 ± 2.0°). The maximum load level of 320 N was reached by all plate constructs and 3 fixator constructs.

CONCLUSION

Our results suggest that the external fixator system allows early but gentle postoperative mobilisation. More aggressive rehabilitation measures should be postponed after the healing of the fracture.

Focus on stability: biomechanical evaluation of external fixation technique versus locking plate osteosynthesis in 3-part proximal humeral fractures

BACKGROUND

The purpose of this study was to investigate the primary stability and displacement tendencies of an external fixation system in 2 different configurations in comparison to locking plate fixation in a 3-part proximal humeral fracture model.

METHODS

Twenty-one fresh-frozen human cadaveric proximal humeral specimens were divided into 3 groups of 7 stripped specimens. An unstable 3-part fracture of the proximal humerus was set. Construct A consisted of the Galaxy Fixation Shoulder System, with fixation in accordance with the manufacturer's recommended technique (3 pairs of threaded wires). Construct B was fixed with an additional pair of threaded wires according to the recommendations of Gumina et al (4 pairs of threaded wires). The remaining 7 specimens were fixed with a locking plate. By use of an optical motion capture system, relative motion at the fracture site and failure load were evaluated during a cyclic loading protocol.

RESULTS

Plate osteosynthesis showed the highest cyclic load to failure (895 ± 239 N; range, 597-1135 N), followed by construct B (692 ± 121 N; range, 432-788 N) and construct A (350 ± 190 N; range, 139-615 N). Statistically significant differences were found between plating and construct A (P < .001), between plating and construct B (P = .031), and between construct B and construct A (P = .013). Relative motion at the fracture site, in terms of change in distance during cyclic loading, was lowest with construct B measured at the peak load of 395 N after 11 steps (1.73 ± 1.98 mm; range, 0.53-5.96 mm) and highest with construct A (8.46 ± 10.67 mm; range, 2.26-20.79 mm). Angular change measured at the peak load after 11 steps was lowest with construct B (1.19° ± 0.36°; range, 0.59°-1.7°) and highest with construct A (2.44° ± 1.63°; range, 0.77°-4.04°). Statistically significant differences were found between construct A and construct B and between construct A and plating at various steps of cyclic loading.

CONCLUSION

In this biomechanical study of unstable 3-part proximal humeral fractures, locking plate osteosynthesis demonstrated the highest possible load application. External fixator application with 8 threaded wires (construct B) revealed the least relative motion at the fracture site, without a statistically significant difference compared with locking plates. It therefore represents another valid technique for treatment regarding primary stability. The use of external fixator application with 6 threaded wires (construct A) resulted in the lowest stability and the highest rates of displacement.

External fixation can be an option for proximal humerus fractures Neer 3-4

Background:

Proximal humeral fractures (PHF) account for 4-6% of all fractures and 25% of humeral fractures. While conservative treatment is the gold standard for simple fractures, there is no consensus about the best treatment choice for complex PHF in the elderly. Recently a new external fixator was introduced in clinical practice for treatment of complex PHF. Aim of the study was to evaluate the functional results of this therapeutic approach.

Methods:

Data were retrospectively analyzed. Inclusion criteria were: three- and four-part PHF according to Neer, treatment with closed reduction and external fixation, normal Abbreviated Mini Mental Test score, independence in the daily living, non-pathological fracture, glenohumeral joint with moderate osteoarthritic changes and availability of clinical and radiological follow-up. For each patient demographic data, comorbidities, surgery time and estimated blood loss were recorded. Clinical and radiological evaluation were performed at 1, 2, 6, 12 months.

Results:

17 patients were enrolled. Mean age was 69.7 years. Fractures were classified according to Neer as type III in 10 cases and type IV in 7 cases. The mean operating time was 22 minutes. Mean Constant score value at follow up was 74 ± 11,52 at 2 months, 82 ± 11,16 at 6 months and 85 ± 9,86 at 12 months.

Conclusion:

These preliminary results show that the studied system is easy to use, minimally invasive, effective in reducing surgical and hospitalization time. The results in terms of functional recovery are encouraging, showing a reduced number of complications. (www.actabiomedica.it)

Indications and results of osteosynthesis for proximal humerus fragility fractures in elderly patients

Proximal humerus fractures (PHF) are common injuries in the elderly population. Conservative treatment is indicated for undisplaced and stable fractures, which account for almost 80% of the cases. More complex fracture patterns might need surgery, with a wide variety of indication criteria and surgical techniques described in the literature. Surgical treatment should be reserved for patients in good clinical conditions, autonomous in daily living activities and able to adhere to postoperative rehabilitation protocols. In the elderly population with severe osteoporosis, cognitive impairment and clinical comorbidities, the risk of surgical failures is high. In these patients, the choice between surgical and conservative treatment, as well as for the type of procedure, is even more difficult, with no general consensus in the literature. Final indication is usually conditioned by surgeon's experience and preference. Two independent reviewers (B.H and G.G) independently extracted studies on proximal humeral fractures. All selected studies were screened independently (B.H and G.G) based on title and abstract. Then the full text of any article that either judged potentially eligible was acquired and reviewed again. Any disagreement was resolved by discussing the full text manuscripts. Aim of the present paper is to review the literature about indications and results of osteosynthesis for proximal humerus fragility fractures in the elderly population.

Outcomes of 188 Proximal Humeral Fractures Treated with a Dedicated External Fixator with Follow-up Ranging from 2 to 12 Years

BACKGROUND

The treatment of a displaced proximal humeral fracture is still a matter of controversy. Minimally invasive techniques are considered promising options. The purpose of this study was to report outcomes at medium to long-term follow-up after surgical treatment with pins stabilized with an external fixator.

METHODS

A total of 235 patients (average age, 64 years [95% confidence interval (CI), 62 to 65 years]) were treated with closed or open reduction and fixation with pins stabilized by an external fixator specifically designed for proximal humeral fractures. The pins were inserted using a "pins-crossing-fracture" or a "pins-bridging-fracture" technique. One hundred and eighty-eight patients had a minimum radiographic and clinical follow-up of 2 years. Outcomes were assessed using the Oxford Shoulder Score (OSS), the subjective shoulder value (SSV), a visual analog scale (VAS) for pain, and, for 155 patients, the Constant score.

RESULTS

Eighty-one (43%) of the 188 patients had a 2-part fracture, 60 (32%) had a 3-part fracture, and 47 (25%) had a 4-part fracture. The reduction was performed with percutaneous maneuvers in 120 shoulders or a deltopectoral approach, in 68. The external fixator was applied using a "pins-crossing-fracture" technique in 133 shoulders and using a "pins-bridging-fracture" technique in 55. At last follow-up, mean clinical scores were as follows: OSS, 42.6 (95% CI, 42 to 44); SSV, 85.5 (95% CI, 83 to 88); and VAS for pain, 1 (95% CI, 0.7 to 1.2). The complication rate at 3 months was 16% (37 of 235). The most frequent complication was pin-track infection (19 of 235, 8%). A total of 50 patients had ≥1 complication (50 of 188, 27%) and 6 (3%) underwent revision surgery. More complications were observed with the "pins-crossing-fracture" technique.

CONCLUSIONS

In our experience, the use of the external fixator has been a valuable option in the treatment of proximal humeral fractures. The complication and revision rates were acceptable. Most of the complications encountered were manageable without revision surgery.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

A comparative retrospective study of locking plate fixation versus a dedicated external fixator of 3- and 4-part proximal humerus fractures: Results after 5 years

INTRODUCTION

Fractures of the proximal humerus (PHF) represent a common injury among orthopedic department; especially for three- and four-part fractures no consensus about the best treatment is still achieved. The aim of our study was to compare clinical and radiological outcomes in patients alternatively treated with plates and screws or external fixation system for a type III-IV proximal humerus fracture.

MATERIAL AND METHODS

Sixty-nine patients went surgery for type III-IV PHF between January 2011 and January 2014. According to the Neer classification, fractures were classified as type III in 50 cases (72,46%) and type IV in 19 cases (24,56%). 45 patients were treated with plates (65%) and 24 external fixators (35%). The patients' mean age was 62 years (range, 31-87 y). At five years, 60 patients (86,9%) were assessed using the visual analog scale (VAS) pain score, Constant Score (CS), the range of motion, and radiological evaluation. The CS at five years was the primary outcome measure. Results were evaluated and compared with the contralateral unaffected side to avoid bias related to different ages.

RESULTS

At the final follow up, we found no clinical differences when comparing the two procedures. Moreover, when age was considered as a variable, a significative difference of the CS was observed in the group of patients younger than 65 years treated with a plate (Plate Group Mean: 79; SD: +/- 15. Ex Fi Mean: 58; SD:+/- 4. P = 0,008). In the group of patients older than 65 years, the two procedures did not show significative differences in outcomes (Plate Group Mean: 69; SD: +/- 15. Ex Fi Mean: 63; SD:+/- 7. P = 0,032). External fixation procedure was overall associated with a reduction in blood loss, surgical time, length of hospital stay.

CONCLUSION

Percutaneous techniques have a long tradition in PHF treatment; the introduction of dedicated external fixation system has the advantage to improve the stability and allow early rehabilitation when compared to the classical pinning technique. In our experience, the indication elderly patients with osteoporosis and comorbidities may benefit by this type of mini-invasive surgery with low soft tissue damages.

Effect of surgical delay on bacterial colonization in proximal humeral fractures

Postoperative infection is a severe complication after proximal humeral fracture surgical treatment. The aim of this study was to determine if the surgical delay could modify the number and type of bacteria on the surgical site. A two stages study was set up. In the first stage the effect of delay was simulated in 20 patients affected by proximal humeral fracture treated conservatively. In a second stage, the effect of delay was measured in 20 patients that underwent surgery. In stage 1, three skin culture swabs were taken in correspondence of the deltopectoral approach, the day of the fracture (day 0), the day after (day 1), and five days after fracture (day 5). In stage 2, skin swab cultures were taken the day of trauma and immediately before surgery and cultured on various media suitable for aerobic and anaerobic bacteria. The number of bacteria increased over the course of the study, from day 0 to day 5, both considering the total number of colony-forming units and individual species of pathogen bacteria. The second stage of the study confirmed these data. An increasing number of bacteria was observed in patients that underwent surgery later than 2 days from trauma. The delay of surgery increased bacterial colonization of the skin in the deltopectoral approach area including common pathogenic bacteria such as Staphylococcus aureus, coagulase-negative staphylococci and Propionibacterium acnes. This might justify the correlation between delay to surgery and risk of infection. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:942-948, 2016.

Incidence and risk factors for acute infection after proximal humeral fractures: a multicenter study

BACKGROUND

The rate of acute infection after surgery for proximal humeral fractures is not known. The aims of this study were to report the incidence and to analyze the risk factors for infection after proximal humeral fracture treatment.

MATERIALS AND METHODS

We report a retrospective multicenter study of 452 proximal humeral fractures. Data were modeled by use of univariate and/or linear regression analyses to determine the odds ratio (OR). A logistic regression analysis was used to check for demographic and other characteristics with the potential to confound a true association between risk factors and infection.

RESULTS

The mean age was 62.1 years, and 314 patients were female patients. Of the patients, 18 (4%) had an acute infection. The factors that correlated with infection were length of surgery (OR, 1.009; P = .05), preoperative skin preparation with chlorhexidine gluconate (OR, 0.13; P = .008), and prophylactic antibiotic (OR, 10.73; P = .03). The delay to surgery was close to achieving significance (OR, 1.71; P = .06).

CONCLUSION

This study suggests that washing the shoulder with chlorhexidine gluconate and avoiding the use of first-generation cephalosporin in favor of more effective prophylactic therapy are effective at reducing the risk of infection after treatment for proximal humeral fractures.

Incidence and severity of infections after closed reduction and external fixation of proximal humeral fractures

OBJECTIVES

This study aimed to evaluate the incidence and severity of pin tract infections in a series of patients treated by Closed reduction external fixation (CREF) for proximal humeral fractures.

DESIGN

Retrospective review of medical charts and radiographs.

SETTING

Academic level-1 trauma center.

PATIENTS

Forty-six consecutive patients (20 males, 26 females, mean age 50 years (range 20-90 years) with proximal humeral fractures treated by CREF were enrolled into the study based on data retrieved from medical charts and radiographs.

INTERVENTION

None.

MAIN OUTCOME MEASURE

Evaluation of the incidence and severity of post-CREF pin tract infections.

RESULTS

All 46 fractures healed after an average of 4 weeks. There were 18 (39.1%) cases of pin tract infections whose most common bacteria colonization was gram-positive. Pin tract infections were significantly higher among patients with multiple fragment fractures and multiple pins. Treatment consisting of oral or intravenous antibiotics was effective in all cases, and the infection was resolved within 2 weeks at most.

CONCLUSIONS

Most pin tract infections were managed with systemic antibiotics with good results. The occurrence of pin tract infection did not require a change of the stabilization method and none of the patients required revision of their CREF.

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.