Medial Epicondyle Fractures: Biomechanical Evaluation and Clinical Comparison of 3 Fixation Methods Used in Pediatric Patients

Abstract

Background: Screw fixation is the most commonly employed fixation strategy for displaced medial epicondyle fractures, but in younger patients with minimal ossification, the fracture fragment may not accommodate a screw. In these situations, Kirschner-wires (K-wire) or suture anchors may be utilized as alternatives. The purposes of this study were to examine the biomechanical properties of medial epicondyle fractures fixed with a screw, K-wires, or suture anchors, to evaluate clinical outcomes and complications of patients 10 years of age or younger treated with these approaches, and to perform a cost-analysis. Methods: Biomechanical assessment: Immature pig forelimbs underwent an osteotomy through the medial epicondyle apophysis, simulating a fracture. These were then fixed with a screw, K-wires or suture anchors. Cyclic elongation (mm), displacement (mm), load to failure (N), and stiffness (N/mm) were assessed. Clinical assessment: a retrospective review was performed of patients 10 years of age or younger with a medial epicondyle fracture fixed with these strategies. Radiographic outcomes, postoperative data and complications were compared. These data were used to perform a cost-analysis of each treatment approach. Results: Biomechanically, screws were stronger (P=0.047) and stiffer (P=0.01) than the other constructs. Clinically, 51 patients met inclusion criteria (screw=27, wires=11, anchor=13). Patients treated with K-wires were younger (P<0.05) and patients treated with screw fixation had a shorter casting duration (P=0.008). Irrespective of treatment strategy, all fractures healed (100%) and only 1 patient in the screw group lost reduction. Clinical outcomes and complications were similar between groups, but the suture anchor group was less likely to require a second surgery for implant removal (P<0.05). This lower reoperation rate led to a cost-saving of 10%. Conclusions: Biomechanically, all 3 approaches provided initial fixation exceeding the forces observed across the elbow joint with routine motion. The screw construct was the strongest and stiffest. Clinically, all 3 strategies were acceptable, with screw fixation offering a shorter casting duration, but greater implant removal need with higher associated costs.

Clinical study of suture anchors in the treatment of radial head fractures

“…Ettinger et al [ 23 ] believed that the anchor can provide more bone contact and have greater tensile strength. Rickert, Kathleen D and others believed that the biomechanical strength and hardness of screws were better than those of Kirschner wires and screws [ 24 ], which could provide reliable fixation effect. Khazen et al [ 25 ] found that multiple anchors can effectively disperse stress and enhance anti rotation torque.…”

Response to: Medial Epicondyle Fractures: Biomechanical Evaluation and Clinical Comparison of 3 Fixation Methods Used in Pediatric Patients

“…Rickert et al 1 concluded that screw fixation offers a shorter casting duration but reported a casting period of 22 days, which is longer than the 7 to 21 days reported by Stepanovich et al 2 Rickert et al 1 reported extended casting periods of 28 days for the anchor and 33 days for the K-wire group, with dislocation rates of 26%, 31%, and 27% for the screw-wire, anchor-wire, and K-wire group, respectively. We would like to ask Rickert et al 1 why their 3 fixation groups were not mobilized earlier, considering the group's 2 suspected association between elbow stiffness and extended casting.…”

“…Rickert et al 1 wrote that there was no difference between the groups regarding healing at an average of 24.1 weeks without providing a definition for "healing" or data for range of movement, grip strength, referral rate to physical therapy/occupational therapy and return to sport. The authors Rickert et al 1 stated that they had graded complications based on the modified Clavien Dindo classification and that there was no difference between the 3 groups, without providing grading data.…”

“…Suture anchors and K-wires might not offer such a good biomechanical alternative to screw fixation as proposed by Rickert et al, 1 considering that the surgeons did not trust the stability of their fixations to allow earlier mobilization. In Reply:…”

Medial Epicondyle Fractures: Biomechanical Evaluation and Clinical Comparison of 3 Fixation Methods Used in Pediatric Patients

“…We read with interest the recent publication by Rickert et al1 “Medial Epicondyle Fractures: Biomechanical Evaluation and Clinical Comparison of 3 Fixation Methods Used in Pediatric Patients.” Stepanovich et al2 from the same unit as Rickert et al1 reported on screw fixation and nonoperative treatment of medial epicondyle fractures with excellent satisfaction scores for both groups. The authors2 stated that duration of casting was staff dependent, recording 3 to 4 weeks for nonoperative management and 1 to 3 weeks following screw fixation, pointing out that it is their group’s belief that the 3 to 4 weeks used for nonoperative management would likely increase the rate of elbow stiffness when used in fractures associated with a dislocation and that these patients are therefore treated surgically.…”