Session V - Upper Extremity

Clinical Experience with Three Different Retrograde Interlocking Nailing Systems for Humeral Shaft Fractures

Jochen Blum, MD, Martin Runkel, MD, Pol Maria Rommens, MD, PhD

Unfallchirurgie Johannes Gutenberg-Universität Mainz, Mainz, Germany

Purpose: Endomedullary nailing of humeral shaft fractures is a valid treatment especially for fracture types, which are difficult for conservative treatment, like transverse and short oblique fractures. Antegrade nailing systems, e.g. the Seidel nail, are reported to show either problems in rotatory stability and possible nail migration, but also in post-operative shoulder function. The purpose of this study is to evaluate three interlocking nailing systems with retrograde approach for handling qualities, stability, bone healing and functional outcome.

Methods: 168 humeral shaft fractures have been treated with interlocking nails through a retrograde approach. Eighty-one patients were male, 86 female, where one patient had a bilateral fracture. The average age was 54.3 years. In 58 cases a Russell-Taylor nail, in 42 a Synthes prototype of an unreamed humeral nail and in 68 the UHN (unreamed humeral nail) of the AO had been used. There have been 127 fresh fractures, 21 pathological fractures, 16 pseudarthrosis and 4 refractures. A-type fractures were found in 53%, B-type in 29% and C-type in 18% in the non-pathological fractures, with 5% open fractures.

Results: Russell-Taylor group (n=58): 6 patients (10.3%) needed a secondary internal fixation because of bone healing problems. Three times plate osteosynthesis had been performed, in three cases a second intramedullary nail had been used - here in 2 cases with spongious bone transplantation. Postoperative two cases (3.4%) with iatrogenic radial nerve palsy had been seen, where one needed a secondary exploration. Elbow function as final result showed in 82% an excellent, in 9% an acceptable and in 9% a bad result, shoulder function was in 89% excellent, in 8% acceptable and in 3% bad.

Synthes-prototype group (n=42): 3 patients (7.1%) showed bone healing problems. Here in one case plate osteosynthesis was used, in two cases new nails had been used with the new compression device for the UHN. Two cases (4.8%) with iatrogenic radial nerve palsy fully recovered without any further intervention. Elbow function as final result showed in 88% an excellent, in 7% an acceptable and in 5 % a bad result, shoulder function was in 91 % excellent, in 6% acceptable and in 3% bad.

UHN-group (n=68): 5 patients (7.4%) showed bone healing problems. Here in one case spongious bone and new distal interlocking had been performed, in three cases new nails had been used with the new compression device, one with additional spongious bone. One case needed secondary plate osteosynthesis. Three cases (4.4%) with iatrogenic radial nerve palsy fully recovered without any further intervention. Elbow function as final result showed in 89% an excellent, in 8% an acceptable and in 3 % a bad result, shoulder function was in 90% excellent, in 8% acceptable and in 2% bad.

Discussion: Compared to plate osteosynthesis, intraoperative nerve damage had been lower in all three nail types. Concerning bone healing problems, we found slightly more problems in the Russell-Taylor group, which might be caused by the fact that this nail offers only single interlocking proximally and distally. Instead, the UHN is able to increase stability through double interlocking distally and triple interlocking proximally and furthermore can be used together with a specific compression device, which is useful especially in transverse and short oblique fractures.

Differences in elbow function between the Russell-Taylor nail and both unreamed nails find their origin in their different handling together with the insertion-instrumentarium. The Russell-Taylor can cause more damage to the dorsal condylar region because of size and shape of the instrumentarium and the nails design seems to be more adapted for an antegrade than a retrograde approach.

Conclusion: Retrograde interlocked nailing is a very valid method for different kinds of humeral shaft fractures, where conservative treatment is excluded. The unreamed humeral nail (UHN) as a first nail being constructed especially for this approach offers easy and safe handling with good results in bone healing and shoulder and elbow function.