Clinical and radiographic outcome of tension band suture fixation for displaced olecranon fractures.

BACKGROUND: Tension band wire fixation (TBW) is a well-described method for treating displaced olecranon fractures. Further surgery is often needed due to wound breakdown or prominent hardware. An all-suture technique has recently been described as an alternative to TBW but radiographic and clinical outcome are not well established. The aim of this single-center retrospective cohort study was to evaluate outcome after treatment with all-suture technique for simple displaced olecranon fractures. METHODS: A retrospective review of olecranon fractures in patients (> 18 years) treated for displaced olecranon fractures with tension band suture fixation (TBSF) between February and August 2019 was performed in our facility. Primary outcome was revision surgery, which was assessed four years after surgery. Clinical and radiographical follow-up was performed at two weeks, six weeks, three months and six months to assess union rate, fracture displacement, range of motion (ROM), Quick-DASH and Oxford Elbow Score. RESULTS: A total of 24 patients were included. Median age was 64 years [IQR:39-73], 9 patients were male and median ASA score was 2 [IQR:1-2]. 15 fractures were Mayo type 2 A and 9 type 2B with minor comminution. At four-year follow-up, three patients had died. None of the remaining 21 patients had undergone revision surgery. At six months, the median Quick-DASH and Oxford Elbow Score were 2.3 [IQR:0-4.5] and 47 [IQR:46-48], respectively. Median elbow extension and flexion deficits were 0° [IQR:0-2.25] and 0° [IQR:0-0], respectively. Radiographic union was achieved in all patients. In two cases radiographic loss of reduction and malunion was observed but both patients were asymptomatic and had no functional deficits. One patient refractured the elbow due to a second trauma and was reoperated. CONCLUSIONS: TBSF is a promising technique for Mayo type 2 A and 2B fractures with minor comminution. There were no revision surgeries within the first four years. We found good functional outcomes and a high union rate.

Biomechanical comparison of tension band suture fixation and tension band wiring in olecranon fractures.

PURPOSE: Traditional tension band wire fixation (TBWF) of olecranon fractures is associated with high revision rates due to implant-related complications. The purpose of the study was to compare the strength of fixation in olecranon fractures between TBWF and an all-suture based technique. METHODS: A transverse fracture was created in 20 paired fresh-frozen human cadaveric elbows. Fractures were randomly (alternating right-left) assigned for fixation with either tension band suture fixation (TBSF) or TBWF. The elbow was fixed in 90° of flexion and underwent cycling loading by pulling the triceps tendon to 300 N for 200 cycles. Fracture displacement was optically recorded using digital image correlation (DIC). Finally, load-to-failure was assessed by a monotonic pull to 1000 N and failure mechanism was recorded. RESULTS: Two specimens in the TBSF group were excluded from the cycling loading analysis due to technical difficulties with the DIC. After cyclic loading, median (min-max) fracture displacement was 0.28 mm (0.10-0.44) in the TBSF group and 0.18 mm (0.00-1.48) in the TBWF group (p = 0.315). No difference was found between the two groups in the repeated measures analysis of variance (p = 0.329). In the load-to-failure test, 6/10 specimens failed in the TBSF group (median load-to-failure 791 N) vs. 8/10 in the TBWF group (median load-to-failure 747 N). The TBSF constructs failed due to fracture of the dorsal cortex, suture breakage or triceps failure. The TBWF constructs failed due to breakage of the wire. CONCLUSION: There was no difference in fixation strength between the TBWF and TBSF constructs. Our findings suggest TBSF to be a feasible alternative to TBWF and we hypothesize that a non-metallic implant may have fewer implant-related complications. LEVEL OF EVIDENCE: Basic science study.

Suture tension band fixation vs. metallic tension band wiring for patella fractures - A biomechanical study on 19 human cadaveric patellae.

PURPOSE: Traditional tension band fixation of patella fracture is associated with high reoperation rates. The purpose of the study was to assess strength of fixation in patella fractures treated with either a non-metallic all suture-based technique or traditional metallic tension band wiring. METHODS: Ten paired human cadaveric specimens were included. A transverse fracture was created, reduced and fixated with a non-metallic or metallic approach. Non-metallic fixation was done according to a previously published technique, metallic fixation was done according to AO description. Specimens were fixed in 90° of flexion and underwent 200 cycles of loading by pulling the Quadriceps tendon to 300 Newton. Fracture displacement was optically monitored. Primary outcome was fracture displacement after 200 cycles compared to the first cycle. Subsequently, load-to-failure was assessed by a monotonic pull to 1000 N. RESULTS: For cyclic loading analysis, one specimen from each group was excluded due to machine synchronization, resulting in a total population of 18 specimens. Median (min-max) fracture displacement was 0.65 mm (0.06-1.3) in the non-metallic group and 0.68 mm (0-1.23), (p=0.931) in the metallic group. No difference in displacement was found between the two groups in the repeated measures analysis of variance (p=0.5524). For load-to-failure analysis one specimen was excluded due to machine synchronization, resulting a total population of 19 specimens. 2/9 specimens failed in the non-metallic group (at 979 and 635 N) and 2/10 failed in the metallic group (745 and 654 N). CONCLUSION: Non-metallic technique is a biomechanically viable alternative to traditional tension band fixation and it can hopefully lead to fewer implant-related complications.