Okoroha et. al. Henry Ford Hospital, Detroit, MI

Strength Changes Associated with Elongation After Distal Biceps Repair

Kelechi R Okoroha MD, Nathan E Marshall MD, Robert Keller MD, John-Michael Guest MS, Stephanie Muh MD, Vasilios (Bill) Moutzouros MD

Department of Orthopaedic Surgery, Henry Ford Health System, Detroit, Michigan

Objectives

Methods

Results

Discussion

u Advances in surgical fixation of distal biceps ruptures have led to more aggressive post operative therapy

u  Some studies have recommended for early ROM and activities of daily living.

u However, No standard exists, as much of the literature is based on initial fixation strength which does not evaluate lengthening over time

u The purpose of our study was To evaluate the correlation between tendon elongation and biceps strength after distal biceps repair.

u We recruited 11 patients with acute distal biceps ruptures

u Surgery was performed using a single incision technique with a krackow construct and cortical button for fixation

u 2 tantalum beads were implanted : u Bead 1: tendon/radius interface u Bead 2: 1 cm proximal to the first bead

u Lengthening evaluation: u CT and xray at time 0, x rays at 4 and 8 weeks u  Final CT and xray at 16 weeks.

u 7 pts able to return for strength testing at 9 months using a biodex machine.

u Compared supination and flexion strength in the operative arm to the non-operative arm

u Strength measurements were correlated with overall tendon lengthening and lengthening during separate time intervals using correlation coefficients

u The greatest decreases in supination strength showed the strongest correlation with the amount of lengthening in the early post-operative period from 0-4 weeks

u More supination deficits occur if lengthening occured primarily in the early post-operative period (0-4 weeks) as compared to the lengthening occurring in the late recovery phase (8-16 weeks), which preserved supination strength

u Surgical decision making may need a stronger focus on preventing lengthening after distal biceps tendon repair, especially in the early post operative period.

u Tendons may need to be repaired at a greater degree of flexion and even immobilize at this greater degree of flexion

u Additionally, a period of immobilization post-operatively and a delay in physical therapy may aid in reducing early lengthening and also the amount of functional strength loss after distal biceps tendon repair

u Risk of elbow stiffness, however, must be weighed when deciding to prolong immobilization or repair at severe flexion

u On average, flexion strength was 87.7% on the operative side compared to the non-operative side.

u Supination strength was an averaged 77.9% when compared to the non-operative side

u When compared to tendon lengthening, there appeared to be a decrease in strength as the tendon elongates.

u The greatest correlation we noted was in the early post operative period, where supination strength decreased with the amount of lengthening between 0-4 weeks

u There was also a correlation with increased supination strength with elongation from 8-16 weeks.

Table 2. Correlation of overall change in strength with the change in tendon length for the given time periods.

Conclusion

u This study’s findings suggest that all patients undergoing distal biceps tendon repair have significant lengthening after surgery.

u Most of the lengthening was noted in the early post-operative period, in which the greater amount of lengthening correlated with a greater loss of supination strength.

u Further studies will focus on post-operative protocols as they may have an impact on early tendon lengthening and could be adjusted to minimize this consequence on long-term supination strength.

Figure 1:. Correlation of supination strength % with tendon elongation from 0-4 weeks.

Table 3. Overall tendon elongation for each patient showing total tendon elongation as well as elongation at different time points post operatively. Supination and flexion strength percentage of operative side compared to non-operative side.

Variable ValueAge(average) 50years(range:41-57years)Gender 100%male(7/7)RightHanded 71%(5/7)Dominantarminjured 29%(2/7)

0-4 weeks 4-8 weeks 8-16 weeks Total Supination -0.39 0.22 0.81 -0.10Flexion 0.06 0.30 0.02 0.22

Table 1. Demographics. One patient was ambidextrous and injured their right elbow

0%

20%

40%

60%

80%

100%

120%

140%

0 5 10 15 20 25

SupinationStrength

Elongation(mm)0-4Weeks

Figure 2 a-d. a. Time 0 x-ray (left) compared with b. Time 16 week xray (right) showing significant elongation, most significantly from the button to first bead length. c. Time 0 x-ray (left) compared with d. Time 16 week x-ray (right) again showing significant lengthening, however, much less than the case in figure 2a and 2b.

a.

d. c.

b.