Mismatch analysis of humeral nailing: antegrade versus retrograde insertion

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 for humeral shaft fracture: a reproducible technique with the assistance of an external fixator

BACKGROUND

Minimally invasive plate osteosynthesis (MIPO) has become a popular option for treatment of humeral shaft fractures. However, indirect reduction might risk unpromising results, with mal-alignment/mal-union or nonunion. The purpose of this study was to describe a reproducible MIPO technique that used an external fixator during the procedure as a tool for reduction and maintenance, and to assess the outcomes in patients with humeral shaft fracture.

METHODS

Of 31 consecutive cases of humeral shaft fracture in 30 patients, 29 were included in this study. There were seven simple (type A) and 22 comminuted (type B or C) fractures. After the insertion of one Schanz pin on each proximal and distal humerus, a provisional reduction was achieved by connecting the pins with a monolateral external fixator. The MIPO procedure was then performed over the anterior aspect of the humerus. To evaluate the efficacy of the provisional reduction by external fixator, coronal and sagittal alignments were assessed. We also assessed bony and functional results, including complications, from this technique.

RESULTS

There was no case of mal-union >10°, and mean angulation was 1.3° (range 0°-9°) in the coronal plane and 1.2° (range 0°-8°) in the sagittal plane. Twenty-eight of 29 fractures were united, including three delayed unions, with a mean union time of 19.1 weeks (range 12.3-38.4 weeks) and a mean follow-up of 20.8 months (range 13.5-31.0 months). There was one hypertrophic nonunion that healed after fixing with two additional screws. Except one patient with associated injury in the elbow, all patients recovered to pre-injury joint motion. There were two cases of postoperative radial nerve palsy that both recovered completely. We attributed them to manipulation, and not to the Schanz pins or plate fixation.

CONCLUSIONS

Surgical treatment of humeral shaft fractures with external fixator-assisted reduction and MIPO resulted in excellent reductions and high union rates.

An innovative technique of rear entry creation for retrograde humeral nailing: how to avoid iatrogenic comminution

BACKGROUND

Antegrade and retrograde nails are widely used for intramedullary fixation of humeral shaft fractures. Creating the rear entry is the crucial step for retrograde nailing. The common manual technique is associated with considerable risks of additional iatrogenic comminution of the distal humerus.

DESCRIPTION OF THE TECHNIQUE

A specific device for the creation of a rear entry hole has been developed as part of the instruments for humeral shaft nailing (Targon H) and made commercially available (BBraun Aesculap, Germany). After standard triceps-splitting approach, a guide instrument is firmly applied to the distal humerus with one screw. The screw hole is later used for distal interlocking. The oval rear entry hole is then performed by frontal cutter along the guide.

PATIENTS AND METHODS

We have been performing a retrospective evaluation of all unreamed humeral nailings (Targon H) since 2000. Operation time, use of the guide instrument and intra-operative problems were analysed. X-rays were checked for iatrogenic humeral comminution directly after the operation and after physiotherapy. Cases of infection and nonunion were noted.

RESULTS

We identified 87 cases of intramedullary fracture fixation with an interlocking nail (46 antegrade, 41 retrograde). In all retrograde cases a guide instrument and an access reamer were used for the creation of an entry hole. No iatrogenic comminutions were observed during the operation or on postoperative X-rays. Active postoperative exercises were generally allowed in every patient. Mean operative time was shorter for retrograde than for antegrade nailing (90 min vs. 108 min; p = 0.012). We saw two nonunions (2%) and no infections.

CONCLUSIONS

Use of access reamer and guide instrument is a safe and reproducible way of creating a rear entry hole for retrograde humeral nailing. The risk of additional comminution seems to be eliminated.