The safety and feasibility of minimal invasive plate osteosynthesis (MIPO) of the posterior aspect of the humerus: A cadaveric study

Treatment of distal third humeral shaft fractures with posterior minimally invasive plate osteosynthesis (MIPO) with segmental isolation of the radial nerve: minimum one-year follow-up

Background

Open reduction and internal fixation with plate is one of the most widely used treatments for distal third humeral shaft fractures. The purpose of this study was to report the outcomes of the treatment of distal third humeral shaft fractures with posterior minimally invasive plate osteosynthesis (MIPO) with segmental isolation of the radial nerve.

Methods

We performed an observational, retrospective, consecutive, monocentric, continuous multioperator study. We reviewed 22 distal third humeral shaft fractures treated with posterior MIPO in our institution with an extra-articular distal humerus plate from 2018 to 2021. Inclusion was limited to functionally independent patients with displaced fractures involving the junction of the middle and distal thirds of the humerus and minimum 12-month follow-up for implant removal. We assessed clinical outcomes including range of motion; QuickDASH score; Mayo Elbow Performance Score; and Constant-Murley score.

Results

The average follow-up period of the sample was 31.7 ± 11.6 months (range, 15.7-51.3 months). The average elbow flexion and extension were 146.4° ± 7.3° (range, 120°-150°) and -0.7° ± 3.3° (range, -15° to 0°), respectively. The average shoulder anterior flexion, elevation, and abduction were 178.6° ± 3.6° (range, 170°-180°), 179.1° ± 2.9° (range, 170°-180°), and 140.9° ± 14.8° (range, 110°-160°), respectively. The average external rotation was 88.6° ± 6.4 (range, 65°-90°). The mean visual analog scale score for pain was 1.0 ± 1.6 (range, 0-5) and the mean Mayo Elbow Performance Score was 90.5 ± 9.9 (range, 70-100). The mean QuickDASH and Constant-Murley scores were 4.7 ± 6.8 (range, 0-20.5) and 95.5 ± 5.1 (range, 81-100), respectively. Two patients presented with relevant compromise of radial nerve motor function postoperatively (M3 and M2; the more compromised was preoperative injury). All patients recovered radial nerve neuropraxia within six weeks postoperatively. All fractures achieved union. The average anteroposterior and lateral axis were 175.0 ± 3.6 (168.0°-180.0°) and 177.5 ± 2.0 (173.0°-180.0°), respectively. No superficial or deep infection was reported. No cases of re-displacement of fracture, implant failure, or any other implant-related complication in follow-up were reported. No patient required plate withdrawal.

Conclusion

The results of this study demonstrate that the posterior MIPO technique is a reliable option for treating distal third shaft humeral fractures. The radial nerve must be identified and protected in all cases to prevent palsy.

Modified medial minimally invasive double-plating osteosynthesis techniques for the treatment of distal third diaphyseal fracture of humerus

The optimal surgical approach and placement of plates for the treatment of distal third diaphyseal fracture of the humerus are the subjects of debate. The aim of this retrospective study was to evaluate the clinical and radiographic outcomes of modified medial minimally invasive plate osteosynthesis (MIPO) techniques using a double technique for the treatment of distal third diaphyseal fracture of the humerus. A total of 30 patients with a distal third diaphyseal fracture of the humerus were selected from our hospital. Patients were seen between January 2017 and October 2022. They were treated with a modified medial approach combined with MIPO using a double plate technique. Patient demographics, operation time, bleeding volume, union time, complications, the mean fracture length (FL) and distal cortical length (DCL), and the number of screws in the distal fragment were analyzed. The function of the shoulder and elbow was evaluated using Neer's assessment of the shoulder and Mayo's assessment of the elbow. The FL was 56.1 ± 7.2 mm and the DCL was 38.3 ± 5.3 mm. The mean operative time was 84.8 ± 13.4 min (range 60-110 min). The mean blood loss during surgical treatment was 46.5 ± 10.2 ml (range 30-60 ml). Bone healing was observed in all patients from 10 to 16 weeks (average 12.1 ± 1.7) postoperatively, and one case with poor surgical wound healing was recorded. All the patients had good function of both the shoulder and elbow. The maximum flexibility of the elbow ranged from 130° to 145° (average 138.1 ± 4.8°), with a maximum flexibility straightness ranging from 0° to 5° (average 2.2 ± 1.3°). The Mayo elbow joint function score was 80-100 (average 91.4 ± 5.0). The Neer shoulder joint function score ranged from 85 to 100 (average 92.5 ± 3.9). The modified medial approach was beneficial it did not cause any iatrogenic radial nerve or ulnar nerve injuries. The anterior and the medial side plates are fixed perpendicular to the distal humerus and provide excellent stability at the same time producing better shoulder and elbow joint function.

[Translated article] The use of an anatomical implant compared to a straight LCP decreases extraction in posterior humeral MIPO

PURPOSE

Posterior MIPO approach in the humerus has been described by using a 4.5mm LCP plate. Although straight plates have shown good results, they have not been designed to adapt to the distal humeral metaphysis. The goal of the study was to test the null hypothesis that there is no difference in hardware removal after posterior MIPO with either a straight or a pre-contoured plate.

METHODS

Patients older than 18 years, who had suffered mid-distal humeral shaft fracture, were treated by a posterior MIPO technique with a locking plate and had a minimum of 12-month follow-up were retrospectively included. Patients were separated into: group 1 (LCP 4.5mm straight plate); and group 2 (3.5mm anatomically shaped plate). Clinical and radiological evaluations were performed in the postoperative period. Patient-reported outcomes and the need of hardware removal because of pain were assessed.

RESULTS

Sixty-seven patients fulfilled the inclusion criteria. Twenty-seven patients in group 1 and 40 in group 2. No patient was lost to follow-up. There were no statistical differences between in patient reported outcomes measures. All the fractures healed. Within group 1, 18% (95%CI: 6-38%) of the patients required implant removal while in group 2 this incidence was 0% (95%CI: 0-9%) (P 0.009).

CONCLUSION

These results suggest that the use of a 4.5mm LCP compared to an anatomical 3.5mm LCP in posterior MIPO of the humerus generates greater discomfort and therefore leads to a 18% increase in the risk of implant removal.

The use of an anatomical implant compared to a straight LCP decreases extraction in posterior humeral MIPO

PURPOSE

Posterior MIPO approach in the humerus has been described by using a 4.5mm LCP plate. Although straight plates have shown good results, they have not been designed to adapt to the distal humeral metaphysis. The goal of the study was to test the null hypothesis that there is no difference in hardware removal after posterior MIPO with either a straight or a pre-contoured plate.

METHODS

Patients older than 18 years, who had suffered mid-distal humeral shaft fracture, were treated by a posterior MIPO technique with a locking plate and had a minimum of 12-month follow-up were retrospectively included. Patients were separated into: group 1 (LCP 4.5mm straight plate); and group 2 (3.5mm anatomically shaped plate). Clinical and radiological evaluation were performed in the postoperative period. Patient-reported outcomes and the need of hardware removal because of pain were assessed.

RESULTS

Sixty-seven patients fulfilled the inclusion criteria. Twenty-seven patients in group 1 and 40 in group 2. No patient was lost to follow-up. There were no statistical differences between in patient reported outcomes measures. All the fractures healed. Within group 1, 18% (95%CI: 6-38%) of the patients required implant removal while in group 2 this incidence was 0% (95%CI: 0-9%) (P 0.009).

CONCLUSION

These results suggest that the use of a 4.5mm LCP compared to an anatomical 3.5mm LCP in posterior MIPO of the humerus generates greater discomfort and therefore leads to a 18% increase in the risk of implant removal.

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.

Minimally Invasive Plate Osteosynthesis (MIPO) Through the Posterior Approach for the Humerus: A Cadaveric Study

Background Minimally invasive plate osteosynthesis (MIPO) has been effectively used in femur and tibia fractures. MIPO in the humerus is conducted by anterior (most commonly used), lateral, and posterior approaches. However, in the anterior approach, in distal humeral diaphyseal fractures, there is a lack of adequate room for screw placement in the distal fragment for good stability. In such cases, the posterior approach for MIPO may be a propitious treatment method. However, the literature on MIPO using the posterior approach for humeral diaphyseal fractures is limited. This study aimed to evaluate the feasibility of MIPO through the posterior approach and study the association of radial nerve injury with MIPO through the posterior approach for the humerus. Methodology This experimental study was conducted in the Department of Orthopedics, Himalayan Institute of Medical Sciences, Dehradun, Uttarakhand, India, and 20 cadaveric arms (10 right and 10 left) of 11 embalmed (formalin) cadavers were included (seven males and four females). Cadavers were placed prone on the dissection table. The posterolateral tip of the acromion and lateral epicondyle of the humerus were used as bony landmarks that were marked under C-Arm (Ziehm Imaging, Orlando, FL, USA) using K wires (Kirschner wires, Surgical Holdings, Essex, UK). Two incisions on the posterior part of the arm were made, and the radial nerve was identified at the proximal incision. After creating a submuscular tunnel, a 3.5 mm extraarticular distal humeral locking compression plate (LCP) was introduced over the posterior surface of the humerus and fixed to the humerus distally with one screw and then adjusted proximally and fixed to the humerus with another screw in the proximal window, followed by placement of couple more screws under C-Arm. After plate fixation, the dissection was completed to meticulously explore the radial nerve. The radial nerve was examined thoroughly for any injury sustained after completion of dissection, from the triangular interval to the lateral intermuscular septum where the nerve enters the anterior chamber. The position of the radial nerve with respect to plate holes was noted. The distance from the posterolateral tip of the acromion to the lateral epicondyle was measured as humeral length. The medial and lateral points where radial nerve passed over the posterior surface of the humerus were measured from the posterolateral tip of the acromion and compared with the humeral length. Results In this study, the radial nerve was lying over the posterior surface of the humerus for a mean distance of 52.161 ± 5.16 mm. The mean distance at which the radial nerve crossed the medial and lateral borders of the posterior surface of the humerus, measured from the posterolateral tip of the acromion, was 118.34 ± 10.86 mm (40.07% of humeral length) and 170 ± 12.30 mm (57.57% of humeral length), respectively, and the mean humeral length in this study was 295.27 ± 17.94 mm. The radial nerve and its branches were found to be intact in all cases. The radial nerve was related to the fifth, sixth, and seventh holes, with the nerve lying most commonly over the sixth hole (3.5 mm extraarticular distal humerus locking plate). Conclusions The posterior approach of MIPO in humeral fractures is a safe and reliable treatment modality with minimal risk of radial nerve injury. The radial nerve can be safely identified at the spiral groove using the bony landmarks described in our study.

Preoperative position and protection of radial nerve by B-ultrasound combined with MIPPO for treatment of middle-inferior humerus fractures

Background and purpose

Open reduction and internal fixation through the posterior approach are standard methods for treating middle-inferior humerus fractures. Given the limited operative field and difficulty in locating the radial nerve, the minimally invasive percutaneous plate osteosynthesis (MIPPO) technique via the posterior approach to treat middle-inferior humerus fractures has rarely been reported. This study aims to evaluate the clinical effect of the preoperative study of the radial nerve position by B-ultrasound and its intraoperative protection combined with MIPPO in managing middle-inferior humerus fractures.

Methods

The data were studied retrospectively involving 64 participants who had surgery for middle-inferior humerus fractures from the start of 2017 to the end of 2020. Participants were divided into two groups, those treated with the MIPPO technique, including newly developed dual procedures and preoperative position and protection of radial nerve by B-ultrasound (group A), and those treated with open reduction and internal plating fixation (group B).

Results

All the cases were followed up for 12–34 months (an average of 25.6 ± 8.76 months), and there was no significant difference in the mean operative duration, surgical incision infection, range of motion (ROM) and MEPS (Mayo elbow performance score) for groups A and B. However, the occurrence of complications (radial nerve palsy, bone nonunion and flexible internal fixation or ruptures) in group B was significantly higher than the group A. A statistically significant difference was observed in the intraoperative blood loss, hospital stay and fracture nonunion time between the two groups. All the cases gained bone union within the MIPPO group.

Conclusion

MIPPO via the posterior dual approach associated with preoperative position and protection of radial nerve by B-ultrasound does not increase radial nerve injury, however, it exhibits obvious advantages in the bone union, which is worthy of clinical application.

Minimally invasive plate osteosynthesis via posterior approach for type B and C fractures of distal humeral shaft: surgical tactics and a clinical series

The optimal technique and implant for fixation of multifragmentary fractures of the distal humeral shaft remain inconclusive. We describe the use of minimally invasive plate osteosynthesis (MIPO) via posterior approach and extra-articular distal humerus locking compression plate (LCP-EADH) fixation for 18 such fractures. All fractures were united with a mean union time of 17.6 weeks (range 12-20). Transient radial nerve palsy was demonstrated in 2 patients. Six patients had 5° varus angulation and 1 had 5° valgus angulation. Triceps power was Grade 5 in all patients. The mean arc of elbow motion was 127.5 degrees (range 115-140). Six patients had an excellent MEP score and 12 had a good MEP score. As the results, posterior MIPO and LCP-EADH fixation could be an alternative for multifragmentary fractures of the distal humeral shaft, particularly for fractures with a very short distal fragment.

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.

Anterior minimally invasive plating osteosynthesis technique (MIPO) for humeral shaft fractures: an anatomical study of neuromuscular structures at risk

OBJECTIVE

The aim of this study was to evaluate the neuromuscular structures at risk during modified anterior minimally invasive plating osteosynthesis technique (Belangero-Livani) for humeral shaft fractures.

METHODS

Eight fresh-frozen human specimens ranging from 38 to 82 years old were used. Specimens were positioned supine with the shoulder in 70° abduction and the forearm in full supination. Anterior minimally invasive plating osteosynthesis technique according to Belangero-Livani technique was performed in each specimen. Under radioscopic control, the plate was introduced in retrograde fashion through the subbrachialis path. Anatomical structures were inspected and different anatomical parameters were measured after dissection at the end of the surgical procedures. Measurements were performed using a high digital caliper. Statistical analysis was performed using the Pearson's correlation coefficient test. A p value of < 0.05 was used to define statistical significance.

RESULTS

There were no macroscopic lesions of myotendinous or neurovascular structures in any specimen. The mean distance between the radial nerve to the distal lateral end of the plate was 8.63 mm (range 4.14-13.83 mm). The mean total length of the humerus was 328.59 mm. We found a significant direct correlation between the total length of the humerus and both specimen height and weight.

CONCLUSION

The modified Belangero-Livani anterior MIPO technique for humeral shaft fractures performed in retrograde fashion is safe and useful, without major risk to the soft tissue of the anterior compartment of the arm, including the radial nerve in the lateral intermuscular septum. Intraoperative dissection, avoiding deep lateral retraction on the distal approach, minimizes the risk of radial nerve damage. Strict surgical planning and appreciation for the anatomic landmarks can reduce the risk of damage to neuromuscular structures.

LEVEL OF EVIDENCE

Level IV; Case series with no comparison group; Treatment study.