Anteroinferior plating of midshaft clavicular nonunions
Case description
A 51-year-old healthy woman presented with a nonunion of the left clavicle. The initial fracture was sustained 20 years ago and was treated nonoperatively. This resulted in a nonunion with significant limitations in the following 20 years. She used to play tennis (being left-handed) but was no longer able to do so because of the painful shoulder. Also, being a teacher, above shoulder level activities such as writing on the blackboard were impossible for her. Surprisingly, she had not been offered surgical treatment.
Indication
A painful nonunion of the midshaft clavicle is an absolute indication for osteosynthesis. Anteroinferior plate positioning seems to minimize patient discomfort and obviates (in more than 90% of the patients) the need for implant removal.
Preoperative planning
Equipment
Osteotomes
Reduction forceps
Bending pliers for reconstruction plates
Small Hohmann retractors
Oscillating saw
Bone-graft harvesting instruments or some type of commercial bone graft K-wires
Pelvic reconstruction plate 3.5 (standard or locking compression plate (LCP)).
The pelvic reconstruction plates allow for easier contouring to match the serpentine shape of the clavicle.
3.5 mm pelvic reconstruction bending template
3.5 mm cortex screws, 3.5 mm locking screws
(Size of system, instruments, and implants may vary according to anatomy.)
Patient preparation and positioning
The patient lies supine in a beach-chair position with the involved arm freely movable. The head can be secured to a Mayfield headrest. The patient′s head is turned away from the involved clavicle. A towel is placed between the scapulae to make the clavicle more prominent. The entire arm and the ipsilateral side of the chest past the midline are prepared and draped. The ipsi- or contralateral iliac crest is also prepared and draped if anticipating harvesting autogenous cancellous bone grafts. The image intensifier must come from the cranial side of the patient to allow projection of the entire clavicle.
A single dose of 2nd generation cephalosporin should be administered as a prophylactic antibiotic.
Surgical approach
The incision is centered over the nonunion, horizontally and parallel to the inferior edge of the clavicle. In nonunion cases in which the clavicle has been operated on before, having a previous horizontal incision superior to or over the clavicle, the old incision can be used as the skin is mobile enough to position the plate anteroinferiorly. The authors do not identify and isolate the supraclavicular nerves. Although there is a very small potential risk of a postoperative neuroma and/or dysesthesia in the region supplied by these small nerves, the advantage of a clear working area is preferred. Midshaft nonunions are close to the subclavian vessels and the brachial plexus. Especially in case of a hypertrophic nonunion, careful dissection and manipulation of the nonunion site is warranted. Dissection is towards the nonunion, starting in relatively healthy tissue, away from the nonunion. This allows positioning of small Hohmann retractors around the bone. The fibrous nonunion tissue or hypertrophic callus could possibly adhere to the vessels, which can cause tearing of the vessel wall. This carries the potential risk of severe bleeding.