Distal humeral fractures: role of internal fixation and elbow arthroplasty

Distal Humerus Morphological Analysis of Chinese Individuals: A Statistical Shape Modeling Approach

Objective

A detailed analysis of the morphology of distal humeral articulation can help in the creation of anatomic prostheses of hemiarthroplasty. This study used statistical shape modeling to evaluate the 3D morphology of the distal humerus in healthy Chinese individuals and to investigate the proper articular morphology differences.

Methods

A statistical shape model (SSM) of the distal humerus was created using CT scans of 106 survey‐confirmed nonpathologic elbows. In addition, the articular components of each principal component (PC) were selected and fitted on the mean mode. The Euclidean point‐to‐mesh distance of articular modes was calculated as a measurement the proper change in the morphology of the articulation.

Results

The first seven PCs jointly accounted for 80.9% of the total variation (44.4%, 12.2%, 7.9%, 5.9%, 4.1%, 3.4% and 3%, respectively). In the mean model, the distance between the medial and lateral epicondyles was 57.4 mm, the width of the articulation was 42.1 mm, and the angle of the transepicondylar line (TEL) and C line was 4.8°. The articular surface differences of the first PC were significant (RMS: 1.43 mm in the −3 SD model and 2.38 mm in the +3 SD model), whereas under other conditions, the differences were not remarkable despite the maximum deformation not exceeding 1 mm.

Conclusion

A novel method (SSM) was used to evaluate the 3D morphology of the distal humerus in healthy Chinese individuals and investigate the proper articular shape differences. We found the proper shape of articular surface basically transformed into one variation pattern which was relevant to the bone size, even though the morphology of distal humerus possessed complicated variation modes. The findings of this study can be helpful to design the next generation of elbow hemiarthroplasty in the future.

Does preservation of columns affect the medium-term outcome in distal humerus hemiarthroplasty for acute unreconstructable fractures?

BACKGROUND

We assessed distal humeral column preservation effects on clinical, radiographic and patient reported outcomes following distal humerus hemiarthroplasty for acute unreconstructable fractures.

METHODS

Thirty-seven consecutive patients (mean age, 75; range, 29-93 years) with an average follow-up of 61 months (range, 24-105 months) after distal humerus hemiarthroplasty using a triceps preserving approach were studied. QuickDASH and Oxford Elbow Score assessed patient reported outcomes. Clinical and radiographic assessments comprised range of motion, grip strength, instability, implant loosening, chondral wear, heterotopic ossification and condylar union.

RESULTS

Average QuickDASH was 14.9 (range, 0-63) and Oxford Elbow Score 40.35 (range, 25-48). Mean flexion arc was 108°, extension deficit 17° and pronosupination arc 155°. Average operative sided grip strength was 31.05 kg versus 31.13 kg contralaterally. Column preservation had no statistically significant effect on QuickDASH (p = 0.75), Oxford Elbow Score (p = 0.78), flexion-extension (p = 0.87), pronosupination (p = 0.78) or grip strength (p = 0.87). No progressive radiographic loosening or symptomatic chondral wear occurred. All fixed columns united. Three cases of immediate post-operative laxity fully resolved on elbow mobilisation. Four post-operative complications required further surgery: one ulnar neuropathy, one heterotopic ossification, one wound breakdown and one traumatic dislocation.

CONCLUSION

Medium-term outcome of distal humerus hemiarthroplasty for acute unreconstructable distal humeral fractures is reliable irrespective of condylar preservation.

Management of Civilian Low-Velocity Gunshot Injuries to an Extremity

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Despite an increasing rate of civilian low-velocity gunshot injuries, there remains a lack of evidence-based treatment standards.

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Most low-velocity gunshot-induced fractures of the extremity can be managed similarly to non-gunshot-induced fractures, with the goals of restoring function and minimizing complications.

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There are a limited number of high-quality studies to support the use of prophylactic antibiotics for nonoperatively treated gunshot wounds.

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Intra-articular retained bullets should be removed, while prophylactic irrigation and debridement for a transarticular bullet is not routinely warranted for infection prevention.

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Much of the literature on low-velocity gunshot wounds is Level-III or IV evidence, warranting the need for higher-powered, randomized, prospective investigations.

The challenging surgical treatment of closed distal humerus fractures in elderly and octogenarian patients: radiographic and functional outcomes with a minimum follow-up of 24 months

INTRODUCTION

The main purpose of this retrospective, non-randomized, case series study was to evaluate the clinical and radiographic outcomes of distal humerus fractures (DHFs) in a consecutive series of elderly patients operatively treated by two surgeons, and second, to identify proper indications for two elderly age ranges and two fracture pattern groups.

MATERIALS AND METHODS

From January 2009 to June 2014, 51 patients (pts) underwent open reduction and internal fixation (ORIF) using the locking compression plate (LCP) distal humerus plate (DHP) system at our institution. Medical records and radiographs were retrospectively assessed. Patients were divided into 3 groups according to gender, age (pts <85 years, pts ≥85 years) and AO classification (13-B1-B2-C1-C2 or 13-C3). All subjects completed MEPS, Quick-DASH and SF-36 PCS/MCS scores at final follow-up, and statistical analysis was performed.

RESULTS

36 patients (20 women, 16 men), mean age 80.3 years, with AO type 13-B and 13-C DHFs were included with a mean follow-up of 56 months (range 24-92). The most common mechanism of trauma was a fall from ground level (55.6%). The mean MEPS was 78.9 points, Quick-DASH 28.4, SF-36 PCS 48.3 and MCS 48.9. There was statistically significant evidence that having a 13-C3 fracture leads to worse results in MEPS, Quick-DASH and SF-36. The female gender correlates with worse results in SF-36. The patients ≥85 years had a worse prognosis according to Quick-DASH and SF-36, while the AO 13-C3 pattern obtained the worst ROM outcomes versus AO 13 B1-B2-C1-C2 (normal ROM 0°-140°): mean ROM 24°-114° vs 10°-130°, mean flexion deficit 26° vs 10°, mean extension deficit 24° vs 10°, respectively). Complications were presents in 36.1% of patients, overall belonging to the AO type 13-C fracture pattern and to the group ≥85 years.

CONCLUSION

These study data seem to confirm our hypothesis that plate fixation for DHFs guarantees adequate fracture osteosynthesis and satisfactory functional outcomes at medium to long-term follow-up, not only in elderly patients, but also in octogenarian osteoporotic patients (≥85 years) with 13-C1 and 13-C2 fracture patterns, while an alternative solution should be considered for type C3 fractures, even in a primary trauma setting.

Heterotopic ossification after surgery for distal humeral fractures

We retrospectively reviewed 89 consecutive patients (45 men and 44 women) with a mean age at the time of injury of 58 years (18 to 97) who had undergone external fixation after sustaining a unilateral fracture of the distal humerus. Our objectives were to determine the incidence of heterotopic ossification (HO); identify risk factors associated with the development of HO; and characterise the location, severity and resultant functional impairment attributable to the presence of HO. HO was identified in 37 elbows (42%), mostly around the humerus and along the course of the medial collateral ligament. HO was hazy immature in five elbows (13.5%), mature discrete in 20 (54%), extensive mature in 10 (27%), and complete bone bridges were present in two elbows (5.5%). Mild functional impairment occurred in eight patients, moderate in 27 and severe in two. HO was associated with less extension (p = 0.032) and less overall flexion-to-extension movement (p = 0.022); the flexion-to-extension arc was < 100º in 21 elbows (57%) with HO compared with 18 elbows (35%) without HO (p = 0.03). HO was removed surgically in seven elbows. The development of HO was significantly associated with sustaining a head injury (p = 0.015), delayed internal fixation (p = 0.027), the method of fracture fixation (p = 0.039) and the use of bone graft or substitute (p = 0.02).HO continues to be a substantial complication after internal fixation for distal humerus fractures.

Bicolumnar 90-90 plating of low-energy distal humeral fractures in the elderly patient

Fragility fractures of the distal humerus in elderly patients, especially the low transcondylar fracture pattern, can be difficult to optimally manage. Although the fractures are typically low energy resulting in either extra-articular or simple intra-articular patterns, gaining fixation into the distal fragments can be difficult with open reduction internal fixation (ORIF) using traditional 90-90 or parallel plating techniques. Anatomy preserving reconstruction with ORIF is preferred over total elbow arthroplasty (TEA) if possible. In this study, 15 patients were managed with a bicolumnar 90-90 plating construct as a novel method of enhancing distal fixation in these fractures. Fourteen patients went on to radiographic union at an average of 77 days after surgery with an average arc of motion of 105°. One patient was lost to follow-up. Bicolumnar 90-90 plating of distal humerus fractures in elderly patients may represent a viable alternative to traditional ORIF or TEA.

The effect of distal humeral hemiarthroplasty on articular contact of the elbow

BACKGROUND

Hemiarthroplasty is a treatment option for selected distal humerus fractures. The purpose of this study was to determine the effect of distal humeral hemiarthroplasty and implant size on elbow articular contact. We hypothesized that implants of varying sizes produce different contact patterns compared with the native elbow.

METHODS

Eight cadaveric arms were tested in an elbow simulator and the kinematics recorded. Three-dimensional reconstructions of bones and cartilage were generated from computed-tomography images to determine contact patterns. The native articulation was compared to optimal, oversized, and undersized implants (Latitude Anatomic Hemiarthroplasty). Changes in contact patterns relative to the native articulation were measured using total contact area and contact patch agreement scores, defined as the sum of distance between contact patches×area, indicating how well contact patches agree with the native contact pattern.

FINDINGS

The native articulation had significantly lower ulnohumeral contact patch agreement scores compared to all tested implants (P<0.05). Mean ulnohumeral and radiocapitellar contact area decreased an average 44% (P=0.03) and 4% (P=0.07) following placement of an optimally sized implant. There was no effect of implant size on contact area or contact patch agreement score (P>0.05).

INTERPRETATION

Shape differences of elbow implants relative to the native joint may be responsible for altered contact patterns and could be improved with design modifications. These changes may predispose the elbow to arthritis. The lack of influence of implant size suggests that implant shape and materials may be more important than implant sizing during surgery.

Usefulness and reliability of two- and three-dimensional computed tomography in patients older than 65 years with distal humerus fractures

BACKGROUND

Distal humerus fractures are difficult to characterise and to classify according to the AO system. In this multicentre study, our objectives were to assess the usefulness of computed tomography (CT) and to measure intra-observer and inter-observer reliability according to observer experience.

MATERIALS AND METHODS

An online survey of professional practice was performed using a questionnaire based on a clinical case. Participants were asked to determine the AO classification using radiographs then to reappraise their answers after the addition of CT images. For the reliability study, 16 observers in five centres evaluated radiographs and CT scans of 26 distal humerus fractures. They used the radiographs to determine the AO classification and assess the main fracture characteristics then reappraised their findings after adding the CT images. The radiographs and 2D CT images were read twice at an interval of 2 weeks, and during the second reading, 3D CT images were available also. At least 1 month later, the same observers performed similar readings 2 weeks apart (radiographs and 2D CT images at the first reading and addition of 3D CT images at the second reading).

RESULTS

Correct fracture classification was achieved in 95% of cases with the CT images compared to only 73% with the radiographs. CT led to diagnostic and therapeutic changes in 90% and 25% of cases, respectively. Inter-observer reliability was poor for both AO classification and fracture characteristics, not only with the radiographs and 2D CT images, but also with the added 3D CT images. In contrast, intra-observer reliability improved after the addition of 3D CT images. Assessment accuracy was influenced by image quality and geographic origin of the observer but not by observer experience.

CONCLUSION

CT improves diagnostic accuracy and, in some cases, changes the surgical strategy. In our study of a large number of observers, CT did not improve inter-observer agreement about the study variables. Intra-observer agreement was improved by 3D CT but not by 2D CT. Accuracy was not influenced by years of observer experience but was dependent on image quality, proficiency with computer-based tools and, above all, image observation and interpretation.

LEVEL OF EVIDENCE

Level III.

Total elbow arthroplasty for distal humerus fractures

Total elbow arthroplasty has become increasingly popular for the treatment of distal humerus fractures in elderly patients with poor bone quality, comminution, and/or pre-existent elbow abnormalities. The procedure is performed without violating the extensor mechanism; the fractured fragments are exposed and resected on both sides of the triceps, and the components can be implanted through the same exposure. Early outcomes are satisfactory in most elbows and compare favorably with internal fixation in this same group of elderly patients. Advances in elbow arthroplasty for fractures will likely combine refinement of the indications and development of implants with lower rates of failure.