Primary nerve exploration is required in more than 10% of complete motor nerve paralysis cases associated with Gartland type III paediatric supracondylar humerus fractures : a multicentre retrospective study.

Aims: This study aims to determine the prevalence, prognosis, and outcome of complete motor paralysis associated with Gartland type III paediatric supracondylar humerus fractures (SCHFs) and identify when primary nerve exploration is indicated.

Methods: In this multicentre retrospective study, we investigated complete motor paralysis associated with Gartland type III paediatric SCHFs. Iatrogenic paralysis was excluded. Radiographs were used to determine a fascial penetration sign. Findings from nerve explorations were recorded. Notable cases were defined as those with the following nerve conditions: 1) complete or partial laceration; 2) tethering/entrapment; 3) formation of a neuroma; or 4) entrapment at the fracture site or callus. The frequency with which ultrasound was used was documented and its findings were examined.

Results: Among 691 patients with Gartland type III SCHFs, 45 (7%) had complete motor paralysis. Of these, 20 (44%) were managed without primary nerve exploration. Overall, 18 (90%) spontaneously recovered and two (10%) required neurorrhaphy and nerve grafting during a secondary exploration. Of the other 25 (56%) who underwent primary nerve exploration, one had a complete radial nerve laceration, and five had tethered/entrapped nerves. The fascial penetration sign was positive in each of the eight notable cases (18%), a rate that was substantially higher than in the others (19 of 37; p = 0.014, sensitivity 100%, specificity 49%). Ultrasound was used preoperatively in 14 cases (31%) to investigate the condition of the nerve, possible contact with the proximal fragment, and its changes after traction.

Conclusion: For Gartland type III paediatric SCHF patients with complete motor paralysis, we estimate that more than 10% require primary nerve exploration due to tethered/entrapped or lacerated nerves. A positive fascial penetration sign on radiography provided early evidence that primary nerve exploration was warranted. In addition, preoperative ultrasound under general anaesthesia to assess the condition of the nerves can play a crucial role.