**2.3 Hagie pins**

The San Antonio -based Rockwood team described the use of a Modified Rockwood-Hagie pin for treating midshaft clavicular non-unions [15]. This device has been used successfully by a number of groups, with union rates ranging from 91.4 to 100% [16–20]. Mudd et al. [21] reported less favourable results in a small study, with an 83.3% (15/18) union rate. All authors reported that irritation from the prominent lateral end of the implant necessitated removal.

*Intramedullary Fixation of Midshaft Clavicle Fractures DOI: http://dx.doi.org/10.5772/intechopen.112256*

In our experience with this device, the inability to have the length less than 120 mm resulted in prominence of the nuts on the lateral side and often protrusion of the medial end of the screw anteriorly, causing subcuticular irritation, requiring implant removal. We have since chosen devices with more length options that can be made completely intra-osseous, avoiding a second operation to remove the implant. This is also a common problem when plates are used. As the clavicle lies in a subcutaneous plane with little soft tissue and muscular coverage, extra-osseous implants will frequently cause irritation and necessitate a second procedure for removal.

## **2.4 Knowles pins**

Knowles pins are solid threaded nails used to repair midshaft clavicular fractures [22]. Unfortunately, due to their length, one or both ends of the pin frequently protrude from the bone, causing irritation requiring removal after fracture healing.

### **2.5 Echidna pins**

Echidna pins (**Figure 1**) were developed to aid rotational and length stability [23, 24]. The retractable spikes on this intramedullary device can be deployed once in position to achieve fixation in the proximal and distal fragments. While experimental studies have demonstrated good biomechanical performance, this device has not been clinically trialled.

#### **2.6 Solid intra-medullary screws**

Khalil [25] described a medial to lateral approach that made use of a solid 6.5 mm screw, but the prominent medial head caused significant discomfort and additional surgery was needed for implant removal. Abo El Nor [26] used a similar device with

#### **Figure 1.**

*Fluoroscopy images showing intramedullary Echidna pin (a) and Herbert. Screw (b) use to manage a midshaft clavicular fracture.*

a lateral to medial insertion after retrograde drilling of the lateral fragment and achieved a 100% union rate while avoiding the medial head prominence.
