Bicipital tuberosity bone characteristics in surgical reattachment of the distal biceps: anatomical and radiological study

Background: A fracture through the proximal radius is a theoretical concern after cortical button distal biceps fixation in an active patient. The permanent, nonossified cortical defect and medullary tunnel is at risk during a fall eliciting rotational and compressive forces. We hypothesized that during simulated torsion and compression, in comparison with unaltered specimens, the cortical button distal biceps repair model would have decreased torsional and compressive strength and would fracture in the vicinity of the bicipital tuberosity bone tunnel. Methods: Sixteen fourth-generation composite radius Sawbones models were used in this controlled laboratory study. A bone tunnel was created through the bicipital tuberosity to mimic the exact bone tunnel, 8 mm near cortex and 3.2 mm far cortex, made for the BicepsButton distal biceps tendon repair. The radius was then prepared and mounted on either a torsional or compression testing device and compared with undrilled control specimens. Results: Compression tests resulted in average failure loads of 9015.2 N in controls versus 8253.25 N in drilled specimens ( P = .074). Torsional testing resulted in an average failure torque of 27.3 Nm in controls and 19.3 Nm in drilled specimens ( P = .024). Average fracture angle was 35.1° in controls versus 21.1° in drilled. Gross fracture patterns were similar in compression testing; however, in torsional testing all fractures occurred through the bone tunnel in the drilled group. Conclusion: There are weaknesses in the vicinity of the bone tunnel in the proximal radius during biomechanical stress testing which may not be clinically relevant in nature. Clinical Relevance: In cortical button fixation, distal biceps repairs creates a permanent, nonossified cortical defect with tendon interposed in the bone tunnel, which can alter the biomechanical properties of the proximal radius during compressive and torsional loading.

Download Full-text

Minimal Damage to the Supinator Muscle After the Double-Incision Technique for Distal Biceps Tendon Repair

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120967776 ◽

2020 ◽

Vol 8 (12) ◽

pp. 232596712096777

Author(s):

Davide Blonna ◽

Alberto Olivero ◽

Claudia Galletta ◽

Valentina Greco ◽

Filippo Castoldi ◽

...

Keyword(s):

Biceps Tendon ◽

Tendon Repair ◽

Distal Biceps Tendon ◽

Distal Biceps ◽

Supinator Muscle ◽

Fat Fraction ◽

Biceps Tendon Repair ◽

Incision Technique ◽

Bicipital Tuberosity

Background: The effect of the double-incision technique on the supinator muscle is unclear. Purpose: The aim of this study was to quantify fatty atrophy of the supinator muscle and map the area of muscle damage. Study Design: Case series; Level of evidence, 4. Methods: A total of 19 male patients (median age, 43 years) who underwent distal biceps tendon repair were included in the analysis. Patients with a minimum of 12 months of follow-up were included. The following variables were analyzed: range of motion; shortened version of Disabilities of the Arm, Shoulder and Hand (QuickDASH) score; Summary Outcome Determination (SOD) score; and isokinetic peak force and endurance in supination. Quantitative analysis and mapping of fatty infiltration of the supinator muscle were based on the calculation of proton density fat fraction on magnetic resonance imaging scans of both elbows using the IDEAL (Iterative Decomposition of Echoes of Asymmetrical Length) sequence. Results: At an average follow-up of 24 months (range, 12-64 months), the median SOD score was 9.0 (95% CI, 7.8-9.4), and the mean QuickDASH score was 6.7 (95% CI, 0.0-14.1). A difference of 17% in peak torque was measured between repaired and nonrepaired elbows (repaired elbow: 9.7 N·m; nonrepaired elbow: 11.7 N·m; P = .11). Endurance was better in the repaired elbow than the nonrepaired elbow (8.4% vs 14.9% work fatigue, respectively; P = .02). The average fat fraction of the supinator muscle was 19% (95% CI, 16%-21%) in repaired elbows and 14% (95% CI, 13%-16%) in contralateral elbows ( P = .04). The increase in fat fraction was located in a limited area between the radius and ulna at the level of the bicipital tuberosity. Conclusion: The assessment of the supinator muscle showed a limited increase in fat fraction between the radius and ulna at the level of the bicipital tuberosity. No significant effect on supination strength was highlighted.

Download Full-text