Previous studies describing drill trajectory for single incision distal biceps tendon repair suggest aiming ulnar and distal (Lo et al). This suggests that the starting point of the drill would be anterior and radial to the anatomic insertion of the distal biceps tendon. Restoration of the anatomic footprint may be important for restoration of normal strength, especially as full supination is approached. To determine the safest drill trajectory for preventing injury to the posterior interosseous nerve (PIN) when repairing the distal biceps tendon to the ANATOMIC footprint through a single-incision anterior approach utilising cortical button fixation. Through an anterior approach in ten cadaveric specimens, three drill holes were made in the radial tuberosity from the centre of the anatomic footprint with the forearm fully supinated. Holes were made in a 30º distal, transverse and 30º proximal direction. Each hole was made by angling the trajectory from an anterior to posterior and ulnar to radial direction leaving adequate bone on the ulnar side to accommodate an eight-millimetre tunnel. Proximity of each drill trajectory to the PIN was determined by making a second incision on the dorsum of the proximal forearm. A K-wire was passed through each hole and the distance between the PIN and K-wire measured for each trajectory. The PIN was closest to the trajectory K-wires drilled 30° distally (mean distance 5.4 mm), contacting the K-wire in three cases. The transverse drill trajectory resulted in contact with the PIN in one case (mean distance 7.6 mm). The proximal drill trajectory appeared safest with no PIN contact (mean distance 13.3 mm). This was statistically significant with a Friedman statistic of 15.05 (p value of 0.00054). When drilling from the anatomic footprint of the distal biceps tendon the PIN is furthest from a drill trajectory aimed proximally. The drill is aimed radially to minimise blowing out the ulnar cortex of the radius. For any reader inquiries, please contact . vansurgdoc@gmail.com

A larger radial tuberosity, and therefore a smaller radioulnar space, may cause mechanical impingement of the DBT predisposing to tear. We sought to investigate anatomic factors associated with partial DBT tears by retrospectively reviewing 3-T MRI scans of elbows with partial DBT tears and a normal elbow comparison group

3-T MRI scans of elbows with partial DBT tears and elbows with no known pathology were reviewed retrospectively by two independent observers. Basic demographic data were collected and measurements of radial tuberosity length, radial tuberosity thickness, radio-ulnar space, and radial tuberosity-ulnar space were made using simultaneous tracker lines and a standardised technique. The presence or absence of enthesophytes and the presence of a single or double DBT were noted.

26 3-T MRI scans of 26 elbows with partial DBT tears and 30 3-T MRI scans of 30 elbows without pathology were included. Basic demographic data was comparable between the two groups. The tear group showed statistically significant larger mean measurements for radial tuberosity length (24.3mm vs 21.3mm, p=0.002), and radial tuberosity thickness (5.5mm vs 3.7mm, p=<0.0001. The tear group also showed statistically significant smaller measurements for radio-ulnar space (8.2mm vs 10.0mm, p=0.010), and radial tuberosity-ulnar space (7.2mm vs 9.1mm, p=0.013). There was a statistically significant positive correlation between partial DBT tears and presence of enthesophytes (p=0.007) as well as between partial DBT tears and having two discrete DBTs rather than a single or interdigitating tendon (p=<0.0001).

Larger radial tuberosities, and smaller radio-ulnar and radial tuberosity-ulnar spaces are associated with partial DBT tears. This may be due to chronic impingement, tendon delamination and consequent weakness which ultimately leads to tears. Enthesophytes may be associated with tears for the same reason. Having two discrete DBTs that do not interdigitate prior to insertion is also associated with partial tears.

The extracortical single-button (SB) inlay repair is one of the most preferred distal biceps tendon repair techniques. However, specific complications such as neurovascular injury and non-anatomic repairs have led to the development of techniques that utilize intracortical double-button (DB) fixation. To compare the biomechanical stability of the extracortical SB repair with the anatomical DB repair technique. Controlled laboratory study. The distal biceps tendon was transected in 18 cadaveric elbows from 9 donors. One elbow of each donor was randomly assigned to the extracortical SBor anatomical DB group. Both groups were cyclically loaded with 60N over 1000 cycles between 90° of flexion and full extension. The elbow was then fixed in 90° of flexion and the repair construct loaded to failure. Gap-formation and construct stiffness during cyclic loading, and ultimate load to failure was analysed. After 1000 cycles, the anatomical DB technique compared with the extracortical SB technique showed significantly less gap-formation (mean difference 1.2 mm; p=0.017) and significantly more construct stiffness (mean difference 31 N/mm; p=0.023). Ultimate load to failure was not significantly different comparing both groups (SB, 277 N ±92 vs. DB, 285 N ±135; p=0.859). The failure mode in the anatomical DB group was significantly different compared with the extracortical SB technique (p=0.002) and was due to fracture avulsion of the BicepsButton in 7 out of 9 specimens (vs. none in SB group). Our study shows that the intracortical DB technique produces equivalent or superior biomechanical performance to the SB technique. The DB repair technique reduces the risk of nerve injury and better restores the anatomical footprint of biceps tendon. The DB technique may offer a clinically viable alternative to the SB repair technique

Our study aims to demonstrate the efficacy of using endobutton and interference screw technique in the repair of acute distal biceps ruptures. From April 2009 to May 2013, 25 consecutive patients had acute distal biceps tendon repairs using an endobutton and interference screw technique. 3 patients were lost to follow up leaving 22 patients for review. Mean follow up was 24 months (1–51). All were evaluated using a questionnaire, examination, radiographs, power measurements, and Oxford Elbow (OES) and MAYO scores. Overall 95% patients (21/22) felt that their surgery was successful and rated their experience as excellent or good. Mean return to work was 100 days (0–280) and mean postoperative pain relief was 23 days (1–56). 55% returned to sport at their pre-injury level. There was one case (4.5%) of heterotopic calcification with 3 superficial infections (14%). There were no intra or postoperative radial fractures, metalwork failures or metalwork soft tissue irritations. Mean pre-operative OES were 18 (6–37) and post operative 43 (24–48) (p < 0.01). Mean pre-operative Mayo scores were 48 (5–95) and post-operative 95 (80–100) (p < 0.01). Our study supports that distal biceps repairs' with endobutton and interference screw technique appears to lead to high patient satisfaction rates with a relatively early return to function

This is largest collection of outcomes of distal biceps reconstruction in the literature. 8 subjects prospectively measured pre and post reconstruction Strength deficit in patients with chronic tendon deficit is described. To describe outcomes for 53 chronic distal biceps reconstructions with tendon graft. Clinical outcomes as well as strength and endurance in supination and flexion are reported. To examine eight patients measured pre- and post-reconstruction. To identify deficit in supination and flexion in chronic reconstruction. 53 reconstructions of chronic distal biceps with tendon graft were carried out between 1999 and 2015. 26 subjects agreed to undergo strength testing after minimum one year follow up. Eight subjects were tested both before and after reconstruction. Primary outcomes were strength in elbow flexion and forearm supination. Strength testing of supination and flexion included maximum isokinetic power and endurance performed on a Biodex. Clinical outcomes measures included pre-operative retraction severity, surgical fixation technique, postoperative contour, range of motion, subjective satisfaction, SF-12, DASH, MAYO elbow score, ASES and pain VAS Non-parametric data was reported as median (interquartile range), while normally-distributed data was reported as mean with 95% Confidence Limits. Hypothesis testing was performed according to two-tailed, paired t-tests. Median time from index rupture to reconstructions 9.5 (range 3–108) months. Strength measurements were completed at a median follow-up time of 29 (range 12–137) months on 26 subjects. The proportion of patients that achieved 90% strength of the contralateral limb post-reconstruction was 65% (17/26) for peak supination torque, and 62% (16/26) for peak flexion torque. Supination and flexion endurance was 90% of the contralateral arm in 81% (21/26) and 65% (17/26) of subjects, respectively. Ten subjects (39%) achieved 90% strength of the contralateral arm on at least four of five strength tests. Eight of the 26 patients were evaluated pre- and post-surgery. As compared to the contralateral limb, chronic distal biceps rupture was found to have a mean [95%CI] deficit in peak supination torque of 31.0 [21.0, 42.9]% (p=0.002). Mean deficit in peak flexion torque of 34.2 [23.1, 45.4]% (p <0.001). Reconstruction resulted in an increase in peak supination torque of 33.5 [8.7, 58.3]% (p=0.0162), increase in peak flexion torque of 35.0 [6.4, 63.6]% (p=0.023), increase in isometric strength of 57.6 [36.1, 79.1]% (p<0.001), increase in supination endurance of 0.6 [-22.2, 23.4]% (p=0.668), and a decrease in flexion endurance of 4.8 [-23.3, 13.7](p=0.478). Ninety-six percent of the patients (25/26) were satisfied, or very satisfied with the overall outcome of the surgery, while median Mayo score post-reconstruction was 100 (range: 55–100). Chronic distal biceps tendon rupture results in less supination loss and greater flexion loss than previously reported. Reconstruction with tendon graft results in a significant, but incomplete recovery of peak supination and flexion torque, but no significant change in endurance. Clinical patient satisfaction with surgical outcomes is high

Purpose. Based on anatomic studies, it appears that the short head (SH) and long head (LH) of the distal biceps tendons have discreet distal attachments on the radial tuberosity. The SH attaches distally and therefore may function as a stronger flexor, whereas the LH attaches more proximal and ulnar which would make it a greater supinator. The contribution of each of the two heads to flexion and supination has not yet been defined. The rationale of this study was to directly measure the contribution of the SH and LH of the biceps to elbow flexion and forearm supination and provide biomechanical evidence for what is inferred in the anatomical studies. Method. Twelve fresh-frozen cadaveric arms were secured using in vitro elbow simulator, while controlled loads were applied to the individual biceps tendons short and long heads. Isometric supination torque and flexion force were recorded with the forearm in 45 degrees supination, neutral rotation and 45 degrees pronation. Results. In all specimens examined the LH and SH of the distal biceps were important contributors to flexion and supination of the forearm. On average, the SH showed 16% more contribution to flexion for all forearm positions. Torque measurements showed that in pronation and neutral positions the SH contributed 11% more than LH. In the supinated forearm, the SH and LH showed no difference in contribution. A repeated measures analysis of variance (ANOVA) and post-hoc Student-Newman-Keuls tests were used for statistical analysis. Conclusion. In most anatomic studies, it has been suggested that the LH and SH of the distal biceps contribute in different ways to flexion and supination. Based on anatomy only, authors have suggested that the SH is a more important flexor and that the LH is more important in supination. In this biomechanical study we demonstrated that both the LH and SH contribute to flexion and supination. Loss of either the LH or SH will result in weakness in flexion or supination. When assessing contribution to flexion, as anatomic studies suggest, the SH alone is a stronger flexor than the LH. This is most likely due to the fact that the SH has a more distal attachment on the bicipital tuberosity. When assessing contribution to supination, the SH alone was a stronger supinator than the LH consistently in our model. This is in contradiction to previous authors who felt the anatomy of the LH attachment, in a slightly more ulnar position, would make it a stronger supinator