Table 3.

Pearls and pitfalls.

	Pearls	Pitfalls
Ulna osteotomy position and technique We suggest a closing wedge osteotomy, placed as proximal in the ulna as possible	Several authors described a stable situation following ulna osteotomy and fixation only. Osteotomy as proximal as possible: – potentially increases grip due to wider metaphysis in proximal ulna – interosseous ligament pulling forces are increased – Metaphyseal bone healing is overall better Angulation at the metaphyseal level has less effect on reduction, but it permits a finer adjustment. Lengthening of the ulna is necessary to avoid excessive pressure on the radial head	Closed wedge osteotomy may lead to neurological impingement Transverse osteotomy (not bending/elongating) may be associated with a higher risk of radial head redislocation An osteotomy at the centre of rotation and angulation may predispose to non-union
Ulna osteotomy fixation We suggest rigid fixation (LCP plate and locking screws)	Rigid plate fixation: – facilitates early mobilisation – no need for interposition graft According to the tension band principle, a posterior plate may be preferred. External fixation with multidirectional clamps simplifies the attainment of the most satisfactory position of the ulna, since the system can be easily adjusted until a stable reduction has been achieved Intramedullary/radiocapitellar nailing (e.g. Steinman pins): – relatively easy pin removal	Plate removal will be necessary in young patients A lateral location of the plate for ulna fixation may be associated with non-union. An external fixator: – may result in soft tissue contractures – may be less sufficient in a young child – requires multiple frame adaptation under general anaesthesia – may be associated with a higher risk of infection Osteosynthesis materials may break Unfixed ulna osteotomies are associated with high risk of radial head redislocation Pins may migrate or break. Pin infections are rare.
Annular ligament reconstruction (ALR) We suggest to use remnants if possible, or a triceps graft when not available	ALR may contribute to radial head stability Inspection and debridement of the proximal radioulnar joint are possible A triceps graft may be harvested via the incision that had been used for ulna osteotomy	ALR only cannot stabilise the radial head if the forearm is malaligned The use of drill holes may lead to heterotopic ossifications Use of forearm fascia for ALR may lead to a reconstruction that is too weak. ALR has been associated with postoperative loss of pronation Osteolytic changes may be seen; too much tension in ALR may cause hourglass deformation of the radial neck
Transcapittellar K-wire	K-wire fixation may contribute to radial head stability	Radioulnar K-wire fixation may cause heterotopic ossifications interfering with pro-/supination
We suggest that no transcapittellar K-wires should be required following a stable reconstruction. When in doubt, we prefer the use of a radioulnar K-wire.	Radioulnar K-wire fixation: – prevents damage to joint surfaces	Migrating material Material fracture

ALR: annular ligament reconstruction.