Minimally invasive plate osteosynthesis for humeral shaft fracture: a reproducible technique with the assistance of an external fixator

Comparative study of mechanical performance of various fixation constructs in multifragmentary distal humeral shaft fracture: a finite element analysis

BACKGROUND

There has been no scientific mechanical assessment demonstrating the optimal fixation technique in multifragmentary fractures of the distal humeral shaft. The purpose of the present study was to compare the biomechanical performance of 5 fixation constructs as used in minimally invasive plating osteosynthesis (MIPO) for distal humeral shaft fractures.

METHODS

Three-dimensional (3D) humerus model with 20 mm distal humeral shaft fracture gap simulating multifragmentary fracture was created from computed tomography data and virtually fixed by 5 fixation techniques as MIPO, i.e., anterior narrow dynamic compression plate (DCP), anterior narrow locking compression plate (LCP), anterior reversed proximal humeral internal locking system (R-PHILOS), extra-articular distal humerus locking compression plate (LCP-EADH), and anteromedial LCP. All constructs were biomechanically tested under 6 loading conditions by means of finite element analysis, i.e., 250-N axial compression, 7.5-N m internal rotation, 7.5-N m external rotation, 10-N m posterior bending, 10-N m valgus rotation, and 10-N m varus rotation. In addition, A 3D model of each construct was fabricated as 3D printed models. Fixations were applied to the 3D printing model which were later mechanically tested to validate the FE results.

RESULTS

EQV stress exhibited on anterior narrow LCP and anterior R-PHILOS were comparable which were lower than other constructs under axial compression and valgus-varus bending. Anterior R-PHILOS produced lower EQV stress than other constructs under internal-external rotation and posterior bending. On the whole, R-PHILOS demonstrated a comparable fracture displacement to those LCP with anterior or anteromedial approaches, that achieved the lowest displacement values. In addition, the experimental mechanical test values shared a correlation with the FE model results.

CONCLUSION

Overall, the anterior R-PHILOS was considered as a potential candidate for multifragmentary distal humeral shaft fractures. It demonstrated efficacious biomechanical performance in terms of implant stress and distal fragment displacement.

External fixator-assisted plating osteosynthesis in a rabbit model of femoral bone defects appears to be a feasible and reproducible surgical technique: preliminary insights from a bone substitute study

PURPOSE

The aims of this study were to assess the complications associated with the use of an external fixator-assisted plate osteosynthesis technique to stabilize a femoral bone defect in a rabbit model and to evaluate if this technique could avoid the mispositioning and the displacement of the femoral fragments during the surgical procedure.

METHODS

A preliminary cadaveric animal study was conducted to develop a new technique of external fixator-assisted plating. Thirty rabbits underwent a surgical procedure consisting in the creation of a femoral bone defect and, subsequently an implantation of a bone substitute through the assistance of a temporary external fixator. The fixator's ability to maintain length and alignment during surgery was documented. All intraoperative complications were prospectively collected.

RESULTS

No complications related to the use of the temporary external fixator were reported. The technique successfully prevented mispositioning and dislocation during plating in all the rabbits.

CONCLUSION

In a rabbit animal model, the use of an external fixator-assisted plate osteosynthesis technique appears to be feasible and effective in avoiding misposition and rotation of femoral fragments when performing osteotomy and plating to create a mid-diaphyseal femoral defect.

Humerus shaft fractures, approaches and management

Humeral shaft fracture is a common injury which can be treated either conservatively with functional bracing or with surgical fixation. Current evidence shows an increase in the rate of nonunion after conservative treatment, suggesting that indications for conservative treatment may need to be re-examined. This article updates trends in treatment for humeral shaft fracture. Indications for surgery, both for plate osteosynthesis with open reduction and internal fixation (ORIF) as well as for minimally invasive plate osteosynthesis (MIPO) and intramedullary nailing (IMN) are described. Recognition of the advantages and disadvantages of each technique can better define the role of the plate or nail and can aid in the selection of an appropriate surgical approach. ORIF with compression plate continues to have a role in the treatment of simple or AO/OTA type A fractures. The primary goal of minimal invasive osteosynthesis, a surgical technique involving small incisions, closed reduction or mini-open reduction that minimizes soft tissue dissection and helps preserve the periosteal blood supply, is to achieve bone union and the best possible functional outcomes. MIPO of the humerus is now well accepted as being less invasive and providing relative stability to allow indirect (secondary) bone healing with callus formation. MIPO approaches can be performed circumferentially to the humerus, including the proximal, middle and distal shaft. The classic MIPO approach is anterior MIPO, followed by posterior, anterolateral and anteromedial MIPO. IMN is also an option for treating humerus fractures. In the past, IMN was not widely used due to the potential for complications such as shoulder impingement and elbow problems as well as the limited availability of implants and the steep learning curve of this surgical technique. Over the past decade, the launch of a new design of straight antegrade and retrograde IMN with established techniques has encouraged more surgeons to use IMN as an alternative option. Methods of dealing with concomitant and post-treatment radial nerve palsy have also been evolving, including the use of ultrasound for diagnosis of radial nerve conditions. Radial nerves with contusion, entrapment or laceration can be detected using ultrasound with reliability comparable to intraoperative findings. Trends in treatment of radial nerve palsy are described below. Future larger randomized controlled trials comparing conservative and operative management are necessary to further develop appropriate guidelines.

Humeral shaft fracture: systematic review of non-operative and operative treatment

INTRODUCTION

Humeral shaft fractures can be treated non-operatively or operatively. The optimal management is subject to debate. The aim was to compare non-operative and operative treatment of a humeral shaft fracture in terms of fracture healing, complications, and functional outcome.

METHODS

Databases of Embase, Medline ALL, Web-of-Science Core Collection, and the Cochrane Central Register of Controlled Trials (CENTRAL) were systematically searched for publications reporting clinical and functional outcomes of humeral shaft fractures after non-operative treatment with a functional brace or operative treatment by intramedullary nailing (IMN; antegrade or retrograde) or plate osteosynthesis (open plating or minimally invasive). A pooled analysis of the results was performed using MedCalc.

RESULTS

A total of 173 studies, describing 11,868 patients, were included. The fracture healing rate for the non-operative group was 89% (95% confidence interval (CI) 84-92%), 94% (95% CI 92-95%) for the IMN group and 96% (95% CI 95-97%) for the plating group. The rate of secondary radial nerve palsies was 1% in patients treated non-operatively, 3% in the IMN, and 6% in the plating group. Intraoperative complications and implant failures occurred more frequently in the IMN group than in the plating group. The DASH score was the lowest (7/100; 95% CI 1-13) in the minimally invasive plate osteosynthesis group. The Constant-Murley and UCLA shoulder score were the highest [93/100 (95% CI 92-95) and 33/35 (95% CI 32-33), respectively] in the plating group.

CONCLUSION

This study suggests that even though all treatment modalities result in satisfactory outcomes, operative treatment is associated with the most favorable results. Disregarding secondary radial nerve palsy, specifically plate osteosynthesis seems to result in the highest fracture healing rates, least complications, and best functional outcomes compared with the other treatment modalities.

The risk of iatrogenic radial nerve and/or profunda brachii artery injury in anterolateral humeral plating using a 4.5 mm narrow DCP: A cadaveric study

INTRODUCTION

Fixation of humeral shaft fractures with a plate and screws can endanger the neurovascular structure if proper care is not taken. No studies to our knowledge have studied the risk of iatrogenic radial nerve and/or profunda brachii artery (RNPBA) injury from each screw hole of a 4.5 mm narrow dynamic compression plate (narrow DCP). The purpose of this study is to evaluate the risk of RNPBA injury in anterolateral humeral plating with a 4.5 mm narrow DCP.

MATERIAL AND METHODS

18 humeri of 9 fresh-frozen cadavers in the supine position were exposed via the anterolateral approach with 45 degrees of arm abduction. A hypothetical fracture line was marked at the midpoint of each humerus. A precontoured ten-hole 4.5mm narrow DCP was applied to the anterolateral surface of the humerus using the fracture line to position the center of the plate. All screw holes were drilled and screws inserted. The cadaver was then turned over to the prone position with 45 degrees of arm abduction, and the RNPBA exposed. The holes through in which 100% of the screw had contact with or penetrated the RNPBA were identified as dangerous screw holes, while lesser percentages of contact were defined as risky.

RESULTS

The relative distance ratios of the entire humeral length from the lateral epicondyle of the humerus to the 4th, 3rd, 2nd and 1st proximal holes were 0.64, 0.60, 0.56 and 0.52, respectively. The most dangerous screw hole was the 2nd proximal, in which all 18 screws had contacted or penetrated the nerve, followed by the risky 1st (12/18), 3rd (8/18) and 4th (2/18) holes.

CONCLUSION

In humeral shaft plating with the 4.5mm narrow DCP using the anterolateral approach, the 2nd proximal screw hole carries the highest risk of iatrogenic radial nerve and/or profunda brachii artery injury.

Treatment of humeral shaft fractures: a new minimally-invasive plate osteosynthesis versus open reduction and internal fixation: a case control study

Background

To evaluate the feasibility and safety of a new minimally-invasive surgical approach–anteromedial minimally-invasive plate osteosynthesis (MIPO)–in the treatment of middle and distal humeral shaft fractures.

Methods

Fourteen patients with humeral shaft fracture treated with anteromedial MIPO from November 2016 to March 2020 (MIPO Group) were selected as the study subjects. Open reduction and internal fixation (ORIF) were used to treat 14 patients with humeral shaft fractures as the control group (ORIF group). The two groups were fixed with a locking compression plate (LCP) or LCP + multi-directional locking screw system (MDLS). The incision length, intraoperative blood loss, intraoperative fluoroscopy time, operation time, length of hospital stay, fracture healing time, QuickDASH score and Constant score were observed and compared between the two groups.

Results

Fourteen patients were enrolled in each group. The incision length (7.79 ± 2.39 cm), intraoperative blood loss (96.07 ± 14.96 mL), operative time (110.57 ± 21.90 min), hospital stay (6.29 ± 1.49 days) and fracture healing time (14.94 ± 0.99 weeks) in the MIPO group were all lower than those in the ORIF group, and the difference was statistically significant for each parameter (P < 0.05). The intraoperative fluoroscopy time (20.07 ± 3.22) in the MIPO group was significantly higher than that in the ORIF group (P < 0.05). There were no significant differences in age (P = 0.078), QuickDASH score (P = 0.074) or Constant score (P = 0.293) between the two groups and no postoperative complications occurred in any of the patients.

Conclusion

The anteromedial approach MIPO technique has the advantages of less trauma, less bleeding, low risk of nerve injury and high rate of fracture healing. It is one of the most effective methods for the treatment of middle and middle–distal humeral shaft fractures.

Time until union in absolute vs. relative stability MIPO plating in simple humeral shaft fractures

PURPOSE

The objective of this study is to evaluate the effect of absolute stability (AS) versus relative stability (RS) performed through a minimally invasive plate osteosynthesis (MIPO) in AO/OTA 12A1 and 12A2 fractures on healing and the time to radiographic union.

METHODS

This was a retrospective cohort study of all patients treated with plate fixation for AO/OTA type 12A1-A2 fractures at a single institution. Patients were grouped according to the type of stability used in their surgery. Time until radiographic union was estimated using the Kaplan-Meier method, which was compared by long-rank test between both types of surgical techniques.

RESULTS

A total of 70 patients were included in this study with 35 patients in each group. The median follow-up was 9 (IQR 6-14) months. The median time to radiographic union was significantly lower in the AS group than in the RS group: 12 (interquartile range (IQR) 10-14) weeks versus 18 (IQR 16-19) weeks, respectively (p < 0.001). Non-union was seen in two cases (7%) in the relative stability group. Three patients in the RS group developed a post-operative radial nerve palsy.

CONCLUSION

The main finding of this study is that the median time to radiographic union was significantly shorter in the patients treated with AS compared to those with a RS technique. These findings support the recommendations of the AO foundation in that simple metaphyseal fractures (type A) that require surgical treatment should be treated with an AS construct. RS techniques should be reserved to multifragmentary fractures where fragment preservation of blood supply is paramount.

New precontoured long locking plate for proximal metadiaphyseal fractures of the humerus: a cadaveric study for its use with the minimally invasive technique

Background

The purpose of this study was to identify nerves at risk when using a minimally invasive plate osteosynthesis precontoured long proximal humerus locking plate and to evaluate the risk of injury to deltoid insertion and brachialis muscle.

Methods

Ten cadaveric upper limb specimens were used. A transdeltoid anterolateral approach was performed proximally and a second anterior approach was performed distally. A 14-hole “low” long precountored ALPS locking plate (Biomet Trauma; Zimmer Biomet, Warsaw, IN, USA) was used. Subsequently, anatomic dissection to measure the anatomic relationship of the plate with the deltoid insertion, with the brachialis muscle, and with the axillary, radial, and musculocutaneous nerves was performed.

Results

The mean humeral length was 302 mm (standard deviation 52.3, 99% confidence interval: 259.3-344.6). In 6 specimens, the axillary nerve was located at the level of the third row of holes of the plate; in 3 specimens, at the level of the fourth row; and in one specimen, at the level of the second row. The distance between the plate and the musculocutaneous nerve was on average 10.2 mm (standard deviation 4, 99% confidence interval: 6.9-13.5) and between the plate and the radial nerve was on average 7.9 mm (standard deviation 4.7, 99% confidence interval: 4-11.8). The plate pierced the anterior distal fibers of the deltoid in all specimens. In 8 specimens, no brachialis muscle fibers were located under the plate.

Conclusions

The use of the long precontoured 14-hole ALPS locking plate with the minimally invasive plate osteosynthesis technique, previously identifying the axillary and musculocutaneous nerves, is feasible; however, the distances between the plate and the nerves remain low, so caution should be maintained. Despite the curved design of the plate, the deltoid insertion is partially compromised in all cases.

Minimally invasive percutaneous plate osteosynthesis for treatment of proximal humeral shaft fractures

PURPOSE

The objective of this study was to evaluate the feasibility and safety of a minimally invasive percutaneous plate osteosynthesis (MIPPO) procedure for proximal humeral shaft fractures using lateral minimal proximal and distal approaches and lateral bridge plating with primary radial nerve control, and to assess its clinical and radiographic outcomes.

METHODS

A retrospective review was done for the medical records of adult patients admitted for fracture of the proximal humeral shaft without associated injury to the ipsilateral upper limb and who consented to undergo a novel MIPPO technique herein reported. Patients were reviewed at regular follow-up periods and assessed at a final follow-up for evaluation of Constant, normalized Constant, and QuickDASH scores.

RESULTS

There were 21 adult patients with mean age of 56 years. Three patients were lost from early follow-up; one of them had post-operative radial nerve paralysis. Eighteen patients were reviewed for the purpose of this study at a mean of 20 months of final follow-up; among them, one patient developed post-operative radial nerve paralysis with complete recovery after three months. Bone healing was achieved without any malalignment in 17 patients at a mean of 15 weeks, and one patient developed nonunion. At final assessment (mean, 20 months), the mean values of Constant, normalized Constant, and QuickDASH scores were 84 (range, 59 to 100), 95 (range, 73 to 100), and 5 (range, 0 to 18.2) respectively.

CONCLUSION

Compared to pre-reported methods of MIPPO, this technique of lateral proximal and distal mini-approaches with lateral bridge plating after primary control of the radial nerve seems safe and feasible for proximal humeral shaft fractures. It gives good clinical and radiographic results with excellent restoration of upper limb function, very low incidence of post-operative radial nerve injury, and high rate of bone union in good alignment.

Anterior minimally invasive plating osteosynthesis using reversed proximal humeral internal locking system plate for distal humeral shaft fractures

OBJECTIVE

To describe the surgical application of anterior minimally invasive plating osteosynthesis (MIPO) using reversed proximal humerus internal locking system (PHILOS) plate for multifragmentary distal humeral shaft fractures.

METHODS

Twelve patients with distal humeral shaft fractures (type 12B, n = 6 and type 12C, n = 6) were operated on by anterior MIPO and reversed PHILOS plate fixation. The amount of intact bone in the distal fragment was measured by fracture-to-coronoid distance (FCD). Data of the postoperative alignment, complications, union time, and clinical outcomes were collected.

RESULTS

The mean time for fractures to unite in all patients was 14.8 weeks (range 12-22). There was no perioperative complication. The mean FCD was 4.8 cm (range 2.1-8.1). The mean coronal angulation was 3.4° (range 0-9), and the mean sagittal angulation was 1° (range 0-5). All patients had excellent UCLA shoulder score and MEP score results, and the mean range of elbow motion was 140° (range 130-145).

CONCLUSION

Anterior MIPO using reversed PHILOS plate is safe and effective for multifragmentary fractures of the distal humeral shaft even in a fracture with a length of intact bone above the coronoid fossa of only 2 cm.

Is minimally invasive plate osteosynthesis superior to open plating for fixation of two-part fracture of the proximal humerus?

PURPOSE

Displaced two-part fractures of the proximal humerus are generally treated with open plate (OP) fixation. Recently, minimally invasive plate osteosynthesis (MIPO) has been increasingly favored for fracture healing and functional recovery. We aimed to compare OP and MIPO for two-part fractures of the proximal humerus to identify outcome differences.

METHODS

All patients who underwent OP or MIPO for a displaced two-part fracture of the proximal humerus at a single level I trauma center between 2007 and 2013 were retrospectively evaluated. Of the patients, 17 were treated using the OP method through the delto-pectoral approach and 19 with MIPO through deltoid splitting. Radiographic results were evaluated to determine the union rate, time to union, and alignment. Functional outcomes were measured with Constant and UCLA scores. Radiation exposure and operative time were also evaluated.

RESULTS

All patients achieved bone union without complication. In the OP and MIPO groups, no significant difference was observed in the neck shaft angles, constant scores, or UCLA scores. The OP group required less radiation exposure time than the MIPO group ( p < 0.001). However, the OP group showed more operation time than the MIPO group ( p < 0.001).

CONCLUSIONS

Both techniques showed satisfactory radiographic and functional outcomes in two-part fractures of the proximal humerus. Although MIPO technique offers advantages, including minimal soft tissue damage and short operation time, surgeons and patients should be warned of the invisible risk from the radiation hazard.

Geometrical analysis for assessing torsional alignment of humerus

BACKGROUND

Compared to other types of surgeries, minimally invasive surgeries (MISs) of humeral shaft fractures are associated with less radial nerve injury, less soft tissue injury and higher union rate. However, malrotation often occurs in MISs when closed reduction methods are used. This study aims to define specific palpable landmarks to help surgeons determine the correct torsional angle and reduce the incidence of malrotation.

METHODS

Twenty-eight normal humeral computed tomography scans were retrieved from our image database. One line was drawn through the vertices of the intertubercular sulcus of the humeral head in the coronal view, and another line was drawn through the longest axis between the medial and lateral condyles in the coronal view. The angle between these two lines was measured at least 3 times for each scan.

RESULTS

The profile of the intertubercular sulcus tangent line of the humeral head and the axis of the distal humerus was identified as the most accurate method for assessing the precision of torsion during MIS for humeral shaft fractures. The transepicondylar axis line is more internally rotated than the intertubercular sulcus tangent line. The mean angle was measured to be 41.1 degrees.

CONCLUSIONS

The axis of the distal humeral condyles is internally rotated by approximately 41.1 degrees compared with the intertubercular sulcus tangent line of the humeral head. Minimally invasive surgeries can be performed by using these palpable landmarks. The torsional deformities can be reduced with the proper angle adjustment without the need for fluoroscopy. It can also be used to treat unstable comminuted humeral fractures.

LEVEL OF EVIDENCE

Retrospective Study, Diagnostic study, Level III.

Anteromedial minimally invasive plate osteosynthesis (MIPO) for distal third humeral shaft fractures - Is it possible?: A cadaveric study

INTRODUCTION

The purpose of this study was to evaluate the feasibility of the anteromedial minimally invasive plate osteosynthesis (MIPO) approach for distal third humeral shaft fractures and identify neurovascular structures at risk with this approach.

METHODS

Twenty cadaveric arms were fixed with 12-hole precontoured narrow locking compression plates (LCP) with the anteromedial approach using MIPO technique. The proximal approach was done between the biceps and deltoid muscle directly to the bone. The distal approach involved elevating the brachialis from medial intermuscular septum. The plate was inserted beneath the brachialis tunnel from distal to proximal. Three locking screws were fixed at each end through incisions and the rest of screws were inserted percutaneously. The arms were then dissected to identify damage to or direct contact between the screws and brachial artery (BA), median nerve (MN), musculocutaneous nerve (MCN), and radial nerve (RN). The distances from the screws to structures at risk, humeral length, and length of three distal screws in mediolateral (ML) direction were measured.

RESULTS

The average humeral length was 28.97 cm. The average danger zone for the BA and MN were 20.47%-62.66% of the humeral length from the lateral epicondyle, and 20.47%-75.02% for the MCN. The ulnar nerve was not endangered by this approach as it lies posteromedially to the humerus. The danger zone for the RN averaged 27.07%-43.74%, and the most dangerous screw that either penetrated or touched the nerve was at the fifth hole, which lay at 33.14% of the humeral length. The average length of three distal screws in ML direction were 41.4, 25.0 and 22.5 mm.

CONCLUSIONS

The anteromedial MIPO approach can be performed through the internervous plane beneath the brachialis muscle without exposing any nerves or causing any muscle splitting with a 12-hole plate. Both proximal and distal screw insertion must be done with direct exposure. Insertion of percutaneous screws in the middle part of the plate between the two incisions is not possible. This approach could be an alternative for extra-articular distal third humeral shaft fractures which provides less invasive surgical dissection, allows the use of longer distal screws, and achieves better cosmesis.

Minimally Invasive Plate Osteosynthesis of Humeral Shaft Fractures: Current State of the Art

Most closed humeral shaft fractures can be successfully managed nonsurgically. However, fractures for which closed treatment is unsuccessful are stabilized using either plates or intramedullary nails. There are shortcomings associated with each technique, including the potential complications of nonunion, infection, shoulder pain, and radial nerve injury. Minimally invasive plate osteosynthesis (MIPO), an innovative alternative treatment, is gaining in popularity. This technique is based on the anterior humeral shaft providing a relatively safe surface for plate application, and limited open exposures proximally and distally allow percutaneous insertion of the necessary implant. More than 40 articles have been published regarding MIPO, and it compares favorably to other available forms of treatment with excellent functional outcomes and a lower rate of iatrogenic radial nerve injury. Larger randomized controlled trials comparing this method with other accepted techniques, including nonsurgical management, are necessary to better define the role of MIPO in the management of humeral shaft fractures.

Lateral Subcutaneous Locking Compression Plate and Small Incision Reduction for Distal-third Diaphyseal Humerus Fractures

Objective

Iatrogenic radial nerve injury is a great challenge for orthopaedic surgeons who deal with distal‐third diaphyseal humerus fractures. Conventional open reduction and internal fixation (ORIF) remains the gold standard, but complications such as nonunion and iatrogenic radial nerve injury still occur. We fixed the fractures with a lateral locking compression plate (LCP) subcutaneously after small incision reduction to protect the radial nerve. This study reports the clinical and radiographic outcomes of our modified method.

Methods

Thirty‐eight patients with distal‐third diaphyseal humerus fractures were treated with lateral subcutaneous LCP and small incision reduction at our department between September 2013 and August 2016. There were 33 males and 5 females, with an average age of 30.3 years (range, 17 to 49 years). All the cases were types A or B (AO/OTA classification, type A, 24 cases; type B, 14 cases). Among them, 6 cases were combined with preoperative radial nerve palsy. All patients were diagnosed with closed humeral fractures after X‐ray examination, and had typical upper limb pain, swelling, and movement disorders. The operations were performed by a single surgeons’ team. Union time, range of motion (ROM), University of California, Los Angeles (UCLA) shoulder rating scale, and Mayo Elbow Performance Index (MEPI) scores were assessed to evaluate the postoperative results.

Results

All patients were followed up for an average of 11.4 months (range, 3 to 36 months). The average operation time was 75.5 min (range, 60 to 150 min) and average intraoperative radiation exposure was 10.5 s (range, 8 to 18 s). Bony union was achieved in all cases after an average of 16.2 weeks (range, 12 to 25 weeks). No complications such as infection or screw and plate fracture occurred, and no iatrogenic radial nerve injury was observed. According to the UCLA shoulder rating scale, the average score was 33.7 (range, 31 to 35), with 33 excellent (86.8%) and 5 good cases (13.2%). They were all excellent according to their MEPI scores (ranging, 94 to 100, with an average of 97.4). The average operation time for secondary removal of the plate was 15.2 min (range, 10 to 20 min), and no complications such as infection or secondary radial nerve injury occurred.

Conclusions

Lateral subcutaneous LCP and small incision reduction may reduce the risk of iatrogenic radial nerve injury significantly in the treatment of distal‐third diaphyseal humerus fractures. It also leads to solid fixation, good postoperative function, and convenient removal of the plate without injuring the radial nerve.

Comparison between antegrade intramedullary nailing (IMN), open reduction plate osteosynthesis (ORPO) and minimally invasive plate osteosynthesis (MIPO) in treatment of humerus diaphyseal fractures

INTRODUCTION

The three currently used methods of treatment: namely open reduction plate osteosynthesis (ORPO), Minimally invasive plate osteosynthesis (MIPO), antegrade intramedullary nailing(IMN) are all reported as satisfactory procedures for treatment of humeral shaft fractures. However none of the published reports have a comparison of superiority of one procedure over the other. We evaluated the clinical, radiological and functional outcome of the three procedures.

MATERIALS AND METHODS

We studied adult patients with humerus shaft fractures over a period of 2 years from May 2014 to May 2016 in a level 1 trauma center. Forty-four were treated with IMN, 34 treated with ORPO, and 34 with MIPO. The null hypothesis tested in this study is that there is no difference between IMN, ORPO, MIPO with respect to union time, surgical time, complication rate, non-union rate and functional outcome. Functional outcome was studied by comparing the UCLA shoulder and MEP scores in the three groups.

RESULTS

112 patients were studied consisting of 83 males and 29 females with mean age of 39 years (range 18-70). IMN group showed early union with mean of 12.73 weeks compared to MIPO (14.45 weeks) and ORPO(13.58 weeks), (p<0.05). MIPO had no events of non-union, as compared to ORPO (5 non-unions) and IMN (10 non-unions), (p=0.04). The range of movement at the shoulder with the UCLA score was significantly better with a score of 32.26 in MIPO as compared to 27.54 in IMN and 28.82 in ORPO (p<0.05). The difference in MEPS score in the three groups was not significant (p=0.31). IMN required a mean of 117.95 minutes intraoperatively as compared to 131 and 150.58 mins in MIPO, ORPO respectively.

CONCLUSION

MIPO is overall better with respect to non-union, functional outcome and complications rate. The surgical time depends on the surgeons' skill and learning curve. Thus considering the advantages and risks involved in the various procedure and surgical acumen, each case should be individualized to have a good outcome. We advocate that MIPO can be safely used as an alternative in treating these fractures.

Biomechanical Study of the Fixation Strength of Anteromedial Plating for Humeral Shaft Fractures

Background:

Open reduction and internal fixation with plate and screws are the gold standard for the surgical treatment of humeral shaft fractures, this study was to compare the mechanical properties of anteromedial, anterolateral, and posterior plating for humeral shaft fractures.

Methods:

A distal third humeral shaft fracture model was constructed using fourth-generation sawbones (#3404, composite bone). A total of 24 sawbones with a distal third humeral shaft fracture was randomly divided into three Groups: A, B, and C (n = 8 in each group) for anteromedial, anterolateral, and posterior plating, respectively. All sawbones were subjected to horizontal torsional fatigue tests, horizontal torsional and axial compressive fatigue tests, four-point bending fatigue tests in anteroposterior (AP) and mediolateral (ML) directions and horizontal torsional destructive tests.

Results:

In the horizontal torsional fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 6.12°, 6.53°, and 6.81°. In horizontal torsional and axial compressive fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 5.66°, 5.67°, and 6.36°. The mean plate displacement amplitude was 0.05 mm, 0.08 mm, and 0.10 mm. Group A was smaller than Group C (P < 0.05). In AP four-point bending fatigue tests, the mean plate displacement amplitude was 0.16 mm, 0.13 mm, and 0.20 mm. Group B was smaller than Group C (P < 0.05). In ML four-point bending fatigue tests, the mean plate displacement amplitude were 0.16 mm, 0.19 mm, and 0.17 mm. In horizontal torsional destructive tests, the mean torsional rigidity in Groups A, B, and C was 0.82, 0.75, and 0.76 N·m/deg. The yielding torsional angle was 24.50°, 25.70°, and 23.86°. The mean yielding torque was 18.46, 18.05, and 16.83 N·m, respectively.

Conclusions:

Anteromedial plating was superior to anterolateral or posterior plating in all mechanical tests except in AP four-point bending fatigue tests compared to the anterolateral plating group. We can suggest that anteromedial plating is a clinically safe and effective way for humeral shaft fractures.

The treatment of distal third humeral diaphyseal fractures: Is there still a place for the external fixation?

INTRODUCTION

The treatment for humeral diaphyseal fractures is still controversial. The purpose of this study was to evaluate the clinical and radiographic outcomes of treating humeral distal third diaphyseal fractures by using external fixation technique.

MATERIALS AND METHODS

We retrospectively review 65 cases of diaphyseal humeral fractures (31 type A, 23 type B and 11 type C of the AO/OTA classification) treated with external fixation (Orthofix FAD small) between 2008 and 2013. The mean follow-up was 48 months (24-72 months). There were 12 open fractures; however, no cases of concomitant vascular injury were described. The transolecranic traction was always applied to promote partial reduction through ligamentotaxis. In case of interposition of soft tissues impeding reduction, a small incision was performed allowing mobilization of bone ends.

RESULTS

All fractures resulted healed at a mean of 11 weeks (range 9-13 weeks); the average time of removal of the external fixator was 88 days (range 65-95 days). At the last follow-up, the mean elbow flexion was 132.6° (Min 126°-Max 137°) and the mean elbow extension was 6.4° (Max 0°-Min 13°). The Cassebaum's index rated as excellent in 47.8 % (31 patients), good in 37 % (24 patients), fair in 9.2 % (6 patients) and poor in 6 % (4 patients). The mean DASH score at the final follow-up was 14.7 (range 0-33); 15 patients had a range score between 10 and 20, 43 had less than 10, and seven had more than 20. We observed three cases of superficial infections and two cases of acute radial nerve palsy recovered within 3 months.

CONCLUSION

According to the excellent clinical results and full rate of consolidation, we state external fixation as a valid option in the treatment of distal third humeral diaphyseal fractures.

Dual plating for fixation of humeral shaft fractures: A mechanical comparison of various combinations of plate lengths

Objective

The role of plate configuration was found inconclusive on the biomechanical effects of the plate size and hole number for dual plate constructions in humeral shaft fractures. The purpose of this study was to test the biomechanical stability of various dual plate constructions.

Methods

Twenty-four left humeri (4th Generation Composite Humerus, Sawbones, Malmö, Sweden) with comminuted midshaft humeral fracture were used. Four groups of plate constructs were tested: laterally fixed 8-hole locking plate and screws were combined with anteriorly locking plates containing 0, 4, 6, or 8 holes in groups I, II, III, and IV, respectively. The alterations in axial, bending, and torsional angles were recorded.

Results

There were no fixation failures during axial, bending, or torsional stiffness testing within the elastic behavior limits. Axial stiffness was highest in Group IV. Torsional stiffness, posterior-to-anterior bending stiffness, lateral-to-medial bending stiffness, and medial-to-lateral bending stiffness were lowest in Group I.

Conclusion

The similar stiffness values for the 8-to-4 hole and 8-to-6 hole plate constructions indicate that the 8-to-4 hole construction is an option in young adults, while the stiffest 8-to-8 hole combination may be an option for osteoporotic patients.

Fixator-assisted Technique Enables Less Invasive Plate Osteosynthesis in Medial Opening-wedge High Tibial Osteotomy: A Novel Technique

BACKGROUND

Opening-wedge high tibial osteotomy is a well-established procedure in the management of medial osteoarthritis of the knee and correction of proximal tibia vara. Recently, surgical approaches using less invasive plate osteosynthesis have been used with the goal of minimizing complications from more extensive soft tissue exposures. However, to our knowledge, less invasive fixator-assisted plate osteosynthesis has not been tested in the setting of opening-wedge high tibial osteotomy.

QUESTIONS/PURPOSES

The purposes of this study were (1) to assess the complications associated with use of a fixator-assisted less invasive plate osteosynthesis technique to stabilize an opening-wedge high tibial osteotomy in the treatment of proximal tibial vara; and (2) to evaluate the ability of this technique to achieve correction of the proximal tibial deformity and achieve osseous union.

METHODS

From June 2011 to June 2013, a total of 157 limbs in 83 patients who underwent fixator-assisted high tibial osteotomy for (1) idiopathic genu vara; or (2) osteoarthritis of the knee with proximal tibia vara were initially enrolled. Of these, eight limbs (5%) were excluded on the way; thus, 149 limbs in 77 patients were evaluated. During the period in question, no other techniques were used for proximal tibial osteotomy. The surgical procedures included less preparation of soft tissue, proximal tibial osteotomy, application of a temporary external fixator, correction of alignment, and final fixation with the help of an external fixator. Complications were assessed by chart review and the alignment in both coronal and sagittal planes was compared pre- and postoperatively. Radiographic review to confirm osseous union and alignment was performed by two of the authors not involved in clinical care of the patient. Delayed union was described as union occurring later than 4 months.

RESULTS

Thirty limbs out of 149 tibiae (20%) showed complications, all of which were resolved without leaving any sequela. Twenty-seven limbs out of 149 limbs (18%) showed lateral cortical hinge fracture and three limbs out of 149 limbs (2%) showed soft tissue complications (two superficial infections, one wound hematoma). The overall completeness of reaching the target correction was excellent. In the coronal plane, the difference between the amount of real correction and the amount of target correction was 0.3° ± 0.7° (p < 0.001). In the sagittal plane, the difference between pre- and postoperative posterior proximal tibial angle was -0.1° ± 0.2° (p < 0.001). All osteotomies healed before 4 months.

CONCLUSIONS

Fixator-assisted high tibial osteotomy is a valid option for medial opening-wedge high tibial osteotomy, which enables less invasive surgery with excellent coronal/sagittal/rotational alignment control. However, future studies should compare this approach with other approaches for proximal tibial osteotomy to ascertain whether indeed this procedure is less invasive or more reliable.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Posterior minimally invasive plate osteosynthesis (MIPO) of distal third humeral shaft fractures with segmental isolation of the radial nerve

The aim of this study was to evaluate the clinical, radiographic, and functional outcomes of a cohort of patients with distal third humeral shaft fractures treated using a posterior minimally invasive plate osteosynthesis (MIPO) technique. Twenty-one patients were retrospectively evaluated, 13 men and 8 women with an average age of 37 years. The surgery was performed through two posterior incisions away from the fracture site. The radial nerve was identified and protected. The fracture was fixed with a narrow 4.5/5.0mm locking compression plate. After an average follow-up of 22 months, flexion-extension of the elbow was 138°±7°, with a range of motion of 131°. Shoulder motion was 160° in forward flexion, 59° in external rotation, and internal rotation was to the spinous process of 9th thoracic vertebra. Pain severity was 0.5 on the VAS. The DASH score was 9. Average Constant score was 84. MEPI was 97. Fracture union was obtained in all patients. One patient developed transient postoperative radial nerve palsy. These results demonstrate that the posterior MIPO technique is a reliable option for treating distal third humeral shaft fractures.

LEVEL OF EVIDENCE

4.