[Distal humeral fracture in adults: functional evaluation and measurement of isometric strength]

The purpose of the study was to determine prognostic parameters in adult distal humeral fracture.

Thirty patients were reviewed retrospectively at a mean follow-up of 5 years. According to the AO classification there were 5 type A, 5 type B and 20 type C fractures, of which 7 were open. An internal fixation was performed in 27 patients while 3 cases were treated conservatively. An olecranon osteotomy was performed in 8 patients. A bilaterotricipital approach according to Alonso-Llames was performed in 8 cases while 6 times a V-shaped section of the triceps and 3 times a transtricipital approach were performed. A lateral approach and a combined medial and lateral approach were performed one time each. Active-assisted motion begun in 19 patients before the fifth post-op day. Three secondary displacements required reoperation.

The assessment included a questionnaire, a physical as well as radiological examination and measurements of isometric flexion and extension strength of both elbows. Statistical correlations were performed using non parametric tests at a P < 0.05 level.

Average flexion was 127 degrees, while there was an average lack of extension of 29 degrees. Pronation and supination were respectively 68 degrees and 85 degrees. Twenty-two patients were subjectively satisfied with their elbow. The measurements of isometric strength of the fractured elbow showed that the right side which was dominant in the whole population was statistically weaker at follow-up than the left side. This difference was significant for flexion strength (Wilcoxon test P = 0.028) and highly significant for extension strength (Wilcoxon test P = 0.0002). The surgical approaches also influenced strengths. The Alonso-Llames approach was thought to give a better result than the other approaches. Patients mobilized before the fifth post-op day showed a statistically better flexion than patients mobilized later on (exact Fisher test P = 0.013). The difference was not statistically significant for the extension.

The distal humeral fracture produces a decrease of the elbow strength which is more severe for the dominant side. The reason is unknown. The Alonso-Llames approach seems to be the most favorable approach while the V-shaped section of the triceps shows a deleterious effect on strength. Early post-op exercises seem to have a positive effect on the long term ROM. Neither the fracture type (classification) nor the ROM, nor the strength are correlated with the subjective feeling of the patient. On the other hand statistical correlations show that unsatisfied patients are heavy workers (exact Fisher test P = 0.033) and patients younger than 60 years old (exact Fisher test P = 0.029).