Comparison of olecranon plate fixation in osteoporotic bone: do current technologies and designs make a difference?

Olecranon Fractures: A Critical Analysis Review

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Olecranon fractures account for 10% of all elbow fractures and are more likely to result from a low-energy injury. A displaced fracture with a stable ulnohumeral joint (Mayo type 2) is the most common type of injury.

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The management of an isolated olecranon fracture is based on patient factors (age, functional demand, and if medically fit to undergo surgery) and fracture characteristics including displacement, fragmentation, and elbow stability.

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Nonoperative management can be successfully used in undisplaced fractures (Mayo type 1) and in displaced fractures (Mayo type 2) in frail patients with lower functional demands.

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Patients with displaced olecranon fractures with a stable ulnohumeral joint without significant articular surface fragmentation (Mayo type 2A) can be managed with tension band wiring, plate osteosynthesis (PO), intramedullary fixation, or suture repair.

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PO is advocated for multifragmentary fractures and fractures that are associated with ulnohumeral instability. It is essential to consider the variable anatomy of the proximal ulna during surgery.

Biomechanical Comparison of Dual and Posterior Locking Plates in an Ex Vivo Comminuted Olecranon Fracture Model

PURPOSE

Comminuted olecranon fractures are commonly fixed with posterior locking plates (PLPs). Though biomechanically validated, this method comes with risks of symptomatic implant prominence and wound breakdown. Dual locking plates (DLPs) placed on the medial and lateral surfaces of the olecranon theoretically avoid these risks and allow for fixation of proximal fracture fragments in multiple planes. A biomechanical comparison of DLP and PLP fixation would help to validate the use of DLPs in comminuted olecranon fractures.

METHODS

Seven matched pairs of cadaveric upper extremities were evaluated with quantitative computed tomography scans to evaluate bone mineral density (BMD). Osteotomies simulating comminuted olecranon fractures (Mayo Type IIB) were created and the specimens were fixed either with variable angle PLPs or variable angle DLPs. The specimens were then cyclically loaded and loaded to failure. The ultimate strength, fracture displacement, and mechanism of failure were recorded and compared across groups. The correlation between BMD and ultimate strength was analyzed.

RESULTS

The mean total BMD was 0.79 g/cm² (SD, 0.14 g/cm²). No specimen failed during cyclic testing. Five of 7 PLP specimens and 5 of 7 DLP specimens failed by fracture through the proximal screws though in different planes (sagittal vs axial splits, respectively). The mean ultimate strengths of the PLP (1077 N [SD, 462 N]) and DLP (1241 N [SD, 506 N]) groups were similar. There was a linear relationship between ultimate strength and BMD (R² = 0.33).

CONCLUSION

Dual locking plates display biomechanical properties that suggest that they can be used in the fixation of comminuted olecranon fractures. Catastrophic failure of the fixation constructs occurs around stress risers at the proximal screws rather than due to displacement at the fracture itself.

CLINICAL RELEVANCE

Dual locking plate constructs can be considered for use in the fixation of comminuted olecranon fractures.

Case Report: J-Shaped External Fixator for Treatment of Mayo Type II Olecranon Fractures – A Novel Surgical Technique and Report of Clinical Applications

Purpose

We designed a J-shaped external fixator (J-EF) to provide a minimally invasive, one-step surgical method for olecranon fractures. The aim of this study is to retrospectively review the method and the outcomes in 14 patients treated with J-EF fixation.

Methods

Biomechanical comparative study was performed to test the tensile properties of the J-EF using a universal testing machine. Between January 2002 and December 2005, 14 patients (age range: 25–67 years) with Mayo type II olecranon fractures were treated using the external fixation technique. Follow-up was done by standard measures (radiography, range of motion, and complications monitoring) and patient-reported outcomes (Mayo Elbow Performance Score [MEPS] and Disabilities of the Arm, Shoulder, and Hand [DASH] scores) 6 months after surgery. Eight of the patients were reviewed 15 years after the surgery.

Results

Results from biomechanical studies indicate the non-inferiority of J-EF to tension-band wiring (TBW) in tensile properties. At the time of release, the mean elbow flexion arc was 132.5° and the mean forearm rotation arc was 173.6°. The mean DASH score was 14.1 points, and the mean MEPS was 93.9 points. Operative time and intraoperative blood loss were decreased by 41.3% and 64.6%, respectively, in J-EF patients than those in a comparable group treated by TBW. All eight patients are still alive after the surgery and maintaining the original outcome.

Conclusions

External fixation using the J-EF could be considered as an alternative treatment for Mayo type II olecranon fractures as it appears to be a reliable, minimally invasive, and time-saving.

Level of Evidence

Therapeutic Level IV.

Olecranon Fracture in an Older Adult Treated With Locking Plate Osteosynthesis

Although olecranon fractures are not uncommon in the geriatric population, there has been a considerable difference of opinion between surgical and nonsurgical treatments. Surgical treatment is usually deferred in the elderly, even for displaced olecranon fractures, because of inherent risks associated with poor bone quality and soft tissues, which often necessitate further surgeries. However, nonoperative treatment frequently results in an inability to regain full extension strength of the elbow, which can be disabling in select older adults with higher functional demands. We present an active older adult with a displaced olecranon fracture, who achieved a satisfactory result after open reduction and internal fixation (ORIF) using a low-profile locking plate.

Peri-Implant Olecranon Tip Fracture: Complication of Olecranon Osteotomy Plating

Several anatomic plates for fixation of the olecranon after a fracture or an osteotomy are commercially available. They serve as an alternative for tension band wiring, which is associated with a relatively high complication rate. Plating of the olecranon reportedly might result in nonunion or malunion and eventually may require revision surgery or plate removal because of skin irritation. The authors describe a proximal periprosthetic avulsion fracture of the tip of the olecranon as a unique complication associated with the use of an anatomic plate for fixation of an olecranon osteotomy. This retrospective case series included 35 patients with comminuted distal humerus fractures treated by open reduction and internal fixation through an olecranon osteotomy with an anatomic olecranon plate. Of the 35 patients, 6 (17.1%) had postoperative olecranon tip fracture, just proximal to the osteotomy site. In all cases, the fracture line coursed through the proximal cluster of screws situated on the proximal part of the plate. Avulsion fractures of the tip of the olecranon after plating of the olecranon osteotomy could have occurred as a result of biomechanical factors. The short design of the proximal part of the plate and the high screw density in the proximal part of the olecranon could lead to increased mechanical stress during contraction of the triceps. This complication should prompt further biomechanical evaluation of the plate design. [Orthopedics. 2021;44(4):e583-e587.].

Low-profile double plating of unstable osteoporotic olecranon fractures: a biomechanical comparative study

BACKGROUND

In the treatment of unstable olecranon fractures, anatomically preshaped locking plates exhibit superior biomechanical results compared with tension band wiring. However, posterior plating (PP) still is accompanied by high rates of plate removal because of soft-tissue irritation and discomfort. Meanwhile, low-profile plates precontoured for collateral double plating (DP) are available and enable muscular soft-tissue coverage combined with angular-stable fixation. The goal of this study was to biomechanically compare PP with collateral DP for osteosynthesis of unstable osteoporotic fractures.

METHODS

A comminuted displaced Mayo type IIB fracture was created in 8 osteoporotic pairs of fresh-frozen human cadaveric elbows. Pair-wise angular stable fixation was performed by either collateral DP or PP. Biomechanical testing was conducted as a pulling force to the triceps tendon in 90° of elbow flexion. Cyclical load changes between 10 and 300 N were applied at 4 Hz for 50,000 cycles. Afterward, the maximum load was raised by 0.02 N/cycle until construct failure, which was defined as displacement > 2 mm. Besides failure cycles and failure loads, modes of failure were analyzed.

RESULTS

Following DP, a median endurance of 65,370 cycles (range, 2-83,121 cycles) was recorded, which showed no significant difference compared with PP, with 69,311 cycles (range, 150-81,938 cycles) (P = .263). Failure load showed comparable results as well, with 601 N (range, 300-949 N) after DP and 663 N (range, 300-933 N) after PP (P = .237). All PP constructs and 3 of 8 DP constructs failed by proximal fragment cutout, whereas 5 of 8 DP constructs failed by bony triceps avulsion.

CONCLUSION

Angular-stable DP showed comparable biomechanical stability to PP in unstable osteoporotic olecranon fractures under high-cycle loading conditions. Failure due to bony triceps avulsion following DP requires further clinical and biomechanical investigation, for example, on suture augmentation or different screw configurations.

Low-profile double plating versus dorsal LCP in stabilization of the olecranon fractures

INTRODUCTION

Proximal ulna fractures are common in orthopaedic surgery. Comminuted fractures require a high primary stability by the osteosynthesis, to allow an early functional rehabilitation as fast as possible, to reduce long-term limitations of range of motion. Classical dorsal plating is related to wound healing problems due to the prominence of the implant. New low-profile double plates are available addressing the soft tissue problems by positioning the plates at the medial and lateral side. This study analysed whether, under high loading conditions, these new double plates provide an equivalent stability as compared to the rigid olecranon locking compression plate (LCP).

MATERIALS AND METHODS

In Sawbones, Mayo Type IIB fractures were simulated and stabilized by plate osteosyntheses: In group one, two low-profile plates were placed. In group two, a single dorsal plate (LCP) was used. The bones was than cyclically loaded simulating flexion grades of 0°, 30°, 60° and 90° of the elbow joint with increasing tension forces (150 , 150 , 300  and 500 N). The displacement and fracture gap movement were recorded. In the end, in load-to-failure tests, load at failure and mode of failure were determined.

RESULTS

No significant differences were found for the displacement and fracture gap widening during cyclic loading. Under maximum loading, the double plates revealed a comparable load at failure like the single dorsal plate (LCP). The double plates failed with a proximal screw pull-out of the plate, whereas in the LCP group, in 10 out of 12 specimens the mode of failure was a diaphyseal shaft fracture at the distal plate peak.

CONCLUSION

Biomechanically, the double plates are a good alternative to the dorsal LCP providing a high stability under high loading conditions and, at the same, time reducing the soft tissue irritation by a lateral plate position.

Surgical and Nonoperative Management of Olecranon Fractures in the Elderly: A Systematic Review and Meta-Analysis

OBJECTIVES

The aim of this comparative effectiveness study was to perform a meta-analysis of adverse events and outcomes in closed geriatric olecranon fractures, without elbow instability, after treatment with surgical or nonoperative management.

DATA SOURCES

PubMed, Web of Science, and Embase databases.

STUDY SELECTION

Articles were included if they contained clinical data evaluating outcomes in patients ≥65 years of age with closed olecranon fractures, without elbow instability, treated surgically, or with nonoperative management.

DATA EXTRACTION

Data regarding patient age, olecranon fracture type, fracture union, adverse events, reoperation, elbow range of motion, and surgeon and patient reported outcome measures were recorded according to intervention. The interventions included for analysis were tension band wire fixation, plate fixation, or nonoperative management.

DATA SYNTHESIS

Separate random effects meta-analyses were conducted for each outcome according to intervention. Prevalence and 95% confidence intervals were calculated for dichotomous variables, whereas weighted means and confidence intervals were calculated for continuous variables.

CONCLUSIONS

Comparable outcomes were achieved with surgical or nonoperative management of olecranon fractures in geriatric patients. Surgical intervention carried a high risk of reoperation regardless of whether plate or tension band wire fixation was used. Functional nonunion can be anticipated if nonoperative treatment is elected in low-demand elderly patients.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Biomechanical Evaluation of Standard Versus Extended Proximal Fixation Olecranon Plates for Fixation of Olecranon Fractures

Background: Small olecranon fractures present a significant challenge for fixation, which has resulted in development of plates with proximal extension. Olecranon-specific plates with proximal extensions are widely thought to offer superior fixation of small proximal fragments but have distinct disadvantages: larger dissection, increased hardware prominence, and the increased possibility of impingement. Previous biomechanical studies of olecranon fracture fixation have compared methods of fracture fixation, but to date there have been no studies defining olecranon plate fixation strength for standard versus extended olecranon plates. The purpose of this study is to evaluate the biomechanical utility of the extended plate for treatment of olecranon fractures. Methods: Sixteen matched pairs of fresh-frozen human cadaveric elbows were used. Of the 16, 8 matched pairs received a transverse osteotomy including 25% and 8 including 50% of the articular surface on the proximal fragment. One elbow from each pair was randomly assigned to a standard-length plate, and the other elbow in the pair received the extended-length plate, for fixation of the fracture. The ulnae were cyclically loaded and subsequently loaded to failure, with ultimate load, number of cycles, and gap formation recorded. Results: There was no statistically significant difference between the standard and extended fixation plates in simple transverse fractures at either 25% or 50% from the proximal most portion of the articular surface of the olecranon. Conclusion: Standard fixation plates are sufficient for the fixation of small transverse fractures, but caution should be utilized particularly with comminution and nontransverse fracture patterns.

Surgical Management for Olecranon Fractures in Adults: A Systematic Review and Meta-analysis

Olecranon fractures are common upper-extremity fractures amenable to various surgical techniques. The authors conducted a systematic review and meta-analysis to evaluate surgical management strategies for olecranon fractures in adult patients. Two investigators independently screened articles from records obtained from MEDLINE, Embase, SPORTDiscus, CINAHL, and the Cochrane Library databases. The authors compared tension-band wiring (TBW) with plate fixation (PF) for the outcomes of complications and hardware removal. Subgroup analyses were conducted comparing randomized controlled trials with observational studies for each outcome. In addition, the authors evaluated novel fixation techniques other than TBW and PF. Twenty-four studies were included in the systematic review and 10 studies were included in the meta-analysis of TBW vs PF. Compared with TBW (n=270), patients who underwent PF (n=369) had a significantly lower complication rate (relative risk, 0.48; 95% confidence interval, 0.36-0.64; P<.01; I²=16%). Plate fixation (41 of 332) also had less hardware removal compared with TBW (79 of 236; relative risk, 0.36; 95% confidence interval, 0.25-0.50; P<.01; I²=0%). Subgroup analyses showed no difference when comparing randomized controlled trials with observational studies for the outcomes of complication rate (P=.45) and hardware removal (P=.54). Qualitative analysis revealed novel methods of olecranon fixation: a modified cable pin system, tension banding through 2 cannulated screws, olecranon memory connector fixation, and cancellous screw TBW. This meta-analysis revealed significantly lower complication and hardware removal rates for PF compared with TBW. Several novel methods of olecranon fixation may represent viable alternatives. [Orthopedics. 2019; 42(2):75-82.].

Use of an Additional Nonlocking Screw in Olecranon Fracture Osteosynthesis Changes Failure Mechanism

Hardware-related complications can occur when plate fixation is used to stabilize osteoporotic fractures involving the olecranon. The use of an additional nonlocking screw, placed retrograde into the proximal fracture segment, may improve stability under load. The purpose of this study was to conduct a biomechanical comparison of olecranon repair constructs with and without this additional retrograde screw. Nine matched pairs of elderly fresh-frozen cadaveric upper extremities were used. Two-part olecranon fractures were modeled, and fracture stabilization was performed. Olecranon plates were implanted either with the standard surgical technique (CTRL) or with an additional retrograde screw (EXPT). Dynamic extensions of increasingly loaded forearms were performed, and comparisons of sustained cycles, maximum load, and total work were made. Relative motion of bone segments was tracked, and modes of failure were assessed. Seventy-eight percent of specimens from the CTRL group failed due to relative fragment displacement exceeding 3 mm, while 78% of EXPT specimens failed due to instantaneous catastrophic failure. There were no significant differences in terms of number of survived cycles, maximum load, or work performed between the groups. The addition of a retrograde screw in this plating technique changes the failure mode from fracture displacement to catastrophic failure. The use of a 3.5-mm retrograde screw in the relatively small proximal ulnar fragment should be avoided, but screws with a smaller diameter may still have potential to improve fixation. Further biomechanical and clinical research is necessary to improve strategies for plate fixation of olecranon fractures in the elderly population. [Orthopedics. 2019; 42(1):e74-e80.].

Excellent results and low complication rate for anatomic polyaxial locking plates in comminuted proximal ulna fractures

BACKGROUND

Comminuted fractures of the proximal ulna remain a great challenge in orthopedic surgery. The purpose of this study was to report the outcomes of comminuted proximal ulna fractures treated with a new construct type-anatomically preformed polyaxial locking compression plates.

METHODS

Between 2013 and 2016, 46 patients with isolated comminuted fractures were treated with a 2.7-/3.5-mm VA-LCP Olecranon Plate (Synthes, Umkirch, Germany). Of these, 44 were available for an assessment after a mean follow-up period of 2.5 years (range, 12-50 months). We evaluated range of motion, time to recovery, revision rate, and indications, as well as functional scores. Radiographs were analyzed.

RESULTS

The study included 8 Mayo IB, 29 Mayo IIB, and 7 Mayo IIIB fractures. All fractures showed bony union, and only 2 revision surgical procedures were performed because of a new trauma. No other complications occurred. Mean range of motion was 139° (range, 105°-150°), and the mean pain level was less than 1 on a visual analog scale. Regarding elbow function, we found a mean Mayo Elbow Performance Score of 98; a mean Oxford Elbow Score of 44; and a mean Disabilities of the Arm, Shoulder and Hand score of 6. Of the plates, 41% were removed after an average time of 16 months, whereby a significant improvement in extension deficit was detected (P < .01). Ninety-five percent of all patients returned to their pretrauma sports level.

CONCLUSION

The 2.7-/3.5-mm VA-LCP Olecranon Plate represents an effective option with excellent fracture reduction, sufficient stability for early postoperative functional rehabilitation, and a minimum of complications.

Biomechanical Assessment of Locking Plate Fixation of Comminuted Proximal Olecranon Fractures

OBJECTIVES

To determine if mean ultimate strength or failure mechanism differed between comminuted olecranon fractures created at the proximal 25% or 50% of the trochlear notch and fixed with precontoured posterior locking plates (PLPs).

METHODS

Comminuted osteotomies were created in 10 matched pairs of cadaveric upper extremities at either the proximal 25% or 50% of the trochlear notch after quantitative computed tomography scans were performed to evaluate bone mineral density. Variable-angle olecranon PLPs were fixed to the specimens. The triceps tendon of each specimen was loaded cyclically and then to failure. Comparison of mean force at failure (displacement >2 mm) was performed using the 2-tailed t test.

RESULTS

There were no significant differences in specimen bone mineral density within matched pairs. Nineteen specimens failed by olecranon bisection fracture in the sagittal plane. Specimens in the 25% osteotomy group failed at lower ultimate forces of 808 N (SD ± 474 N) versus 1058 N (SD ± 480 N) in the 50% osteotomy group (P = 0.044).

CONCLUSIONS

The ultimate strength of comminuted olecranon fracture fixation with a PLP decreases significantly if the fracture is proximal to the midpoint of the trochlear notch. Fractures proximal to the midpoint of the trochlear notch may benefit from supplemental fixation or suture augmentation to prevent failure, particularly at force ranges higher than those experienced during active elbow range of motion.

Outcome after olecranon fracture repair: Does construct type matter?

PURPOSE

This study compares clinical and functional outcomes of patients with displaced olecranon fractures treated with either tension band wiring (TBW) or a hook plate construct.

METHODS

We performed a retrospective review of olecranon fractures operatively treated with either TBW or plate fixation (PF) using a hook plate over a 7-year period. Patient demographics, injury information, and surgical management were recorded. Fractures were classified according to the Mayo system. Measured outcomes included range of elbow motion, time to union, and development of postoperative complications. Mayo Elbow Performance Index (MEPI) scores were obtained for all patients. All patients were followed for a minimum of 6 months.

RESULTS

A total of 48 patients were included in this study, 23 treated with TBW and 25 treated with hook PF. Groups did not differ with respect to patient demographics, Mayo fracture type, or duration of follow-up. Patients undergoing PF had less terminal extension than TBW patients (-8.6° ± 7° vs. -3.5° ± 9.3°, p = 0.036) and a longer time to radiographic union (19 ± 8 vs. 12 ± 6 weeks, p = 0.001). There were no differences in rates of symptomatic hardware, MEPI scores, or other clinical outcomes. Two patients in each group required a second surgery.

CONCLUSIONS

TBW and PF of olecranon fractures had similarly excellent functional outcomes in this study. Patients undergoing PF had a longer time to union and slightly worse extension at final follow-up. TBW remains an effective treatment for appropriately selected olecranon fractures and in this cohort outperformed plate osteosynthesis.

Olecranon Fractures

Olecranon fractures are common upper extremity injuries, with all but nondisplaced fractures treated surgically. There has been a recent shift in the surgical management of these fractures from tension band wiring to locking plate fixation and intramedullary nailing; however, this comes with increased implant cost. Although most patients can expect good outcomes after these various techniques, there is little information to guide a surgeon's treatment plan. This article reviews the epidemiology, classification, treatment, and outcomes of olecranon fractures.

Critical analysis of olecranon fracture management by pre-contoured locking plates

BACKGROUND

Fractures of the proximal ulna are rare and usually managed surgically. Strong fixation of the harware is essential to obtain good outcomes. We report our experience with pre-contoured locking plate fixation of complex olecranon fractures and present a critical appraisal of the outcomes.

HYPOTHESIS

Pre-contoured locking plates provide good outcomes, but their clinical tolerance may be limited in some instances.

MATERIALS AND METHODS

From September 2009 to December 2011, 28 patients were managed using a pre-contoured locking compression plate (LCP(®)). Among them, 6 were excluded because of missing data, which left 22 patients (11 males and 11 females) with a mean age of 55.7 years, including 12 who were employed. The fracture was on the dominant side in 11 patients. According to the Mayo Clinic classification, 15 fractures were type II and 7 type III. In addition to the ulnar fracture, a radial head fracture was present in 9 patients and a coronoid process fracture in 5 patients. Functional recovery was assessed using the Broberg-Morrey score and Mayo Elbow Performance Score (MEPS). Radiographs were obtained to evaluate the quality of fracture reduction and fracture healing, as well as to look for ossifications and osteoarthritis.

RESULTS

Mean follow-up was 20 months. Flexion was 131°, extension loss was 9.5°, pronation was 79°, and supination was 80.5°. The mean Broberg-Morrey score was 96.7 and the mean MEPS score 96.6. Fracture healing occurred in all patients, within a mean of 10.6 weeks. Evidence of early osteoarthritis was found in 6 patients, ossifications in 3 patients, and synostosis in 1 patient. An infection was successfully treated with lavage and antibiotic therapy in 1 patient. The fixation hardware was removed in 6 patients. No prognostic factors were identified.

DISCUSSION-CONCLUSION

Our hypothesis was confirmed. The outcomes are encouraging and comparable to those reported in the literature. The critical issue is the limited clinical tolerance of the plate with a high rate of posterior impingement requiring plate removal (27%). Rigorous technique is essential during plate implantation.

LEVEL OF EVIDENCE

Level IV, retrospective study.

Biomechanical evaluation of two innovative locking implants for comminuted olecranon fractures under high-cycle loading conditions

INTRODUCTION

The relatively high complication rate after fixation of olecranon fractures has led to an increasing application of anatomically pre-contoured locking plate systems. The purpose of the present study was to conduct a biomechanical comparison of olecranon osteosyntheses by applying the Olecranon VA-LCP and the 3.5mm LCP Hook Plate (LCP, locking compression plate) to an unstable fracture model under high-cycle loading conditions.

METHODS

After creating an unstable fracture (Schatzker type B), osteosynthesis was performed on eight pairs of fresh-frozen cadaveric ulnae by application of either the Olecranon VA-LCP (Synthes, Solothurn, Switzerland) or the 3.5mm LCP Hook Plate (Synthes, Solothurn, Switzerland). Loading (50,000 alternating loads, cyclic and sinusoidal 10-300 N) was conducted by application of tensile load with the elbow in 90° flexion to simulate the tensile strength of the triceps brachii. For statistical analysis, angular displacement in the region of the humeral trochlea was taken as a measure of olecranon dislocation.

RESULTS

In Group 1 (Olecranon VA-LCP), a median angular displacement of 0.36° (minimum 0.10°; maximum 0.80°) was observed after 500 alternating loads. In Group 2 (3.5-mm LCP Hook Plate), the medial displacement was 0.80° (minimum 0.13°; maximum 2.72°). The difference was nonsignificant (p = 0.128). The mean value for angular displacement in Group 1 after 50,000 cycles was 0.80° (minimum 0.31°; maximum 1.99°), whereas in Group 2 a mean angular displacement of 2.02° (minimum 0.71°; maximum 6.40°) was recorded. The difference was statistically significant (p = 0.017). In Group 2, implant failure in the form of proximal plate pullout occurred in one construct after 756 cycles.

CONCLUSION

A significantly higher biomechanical stability can be achieved in the fixation of unstable olecranon fractures by application of the Olecranon VA-LCP rather than the 3.5mm LCP Hook Plate.

Locking-plate osteosynthesis versus intramedullary nailing for fixation of olecranon fractures: a biomechanical study

PURPOSE

Intramedullary nailing and locked plating for fixation of olecranon fractures has recently gained popularity. However, these two new technologies have not been compared for their biomechanical efficacy. The aim of this study was to evaluate the biomechanical stability of two newly designed fracture fixation devices for treating olecranon fractures during dynamic continuous loading: the ION intramedullary locking nail and the LCP precontoured locking compression plate.

METHODS

Simulated oblique olecranon fractures were created in eight pairs of fresh-frozen cadaver ulnae and stabilised using either the LCP or ION. Specimens were then subjected to continuous dynamic loading (from 25 to 200 N), with a continuous angle alteration between 0° and 90° of flexion, to perform a matched-pairs comparison. Significant differences in the distance between markers surrounding the fracture gap was determined using the Wilcoxon test after four and 300 loading cycles.

RESULTS

The ION resulted in significantly less displacement in the fracture gap at 0° extension (P = 0.036), 45° flexion (P = 0.035) and 90° flexion (P = 0.017) after 300 cycles of continuous loading. The measured displacements were small and were probably not of clinical significance. No mechanical failure or hardware migration was seen with either fixation technique.

CONCLUSION

This study shows significantly less micromotion for the ION than for the LCP in treating oblique olecranon fractures after 300 cycles of dynamic loading. Both implant types could be appropriate surgical techniques for fixation of selected olecranon fractures and osteotomies.

Olecranon fractures

Olecranon fractures are common injuries of the upper extremity; majority are treated surgically. A variety of fixation techniques are available to surgeons in modern practice, but there is little comparative clinical research to guide one's decision. Nonetheless, good results over all are to be expected after surgical management. This article presents a review of the current understanding and available evidence in the treatment of olecranon fractures, their relevant anatomy, fracture patterns, fixation options, and outcomes.