Distal Humeral Articular Surface Research Articles

Olecranon Osteotomy Exposure for Distal Humeral Fracture Treatment.

Olecranon osteotomy (OO) is commonly utilized to improve exposure when treating intra-articular distal humeral fractures. A chevron-shaped osteotomy facilitates reduction and increases surface area for healing1. Following distal humeral fracture reduction and fixation, the OO fragment is fixed with a precontoured plate. The OO technique yields comparable outcomes to alternative techniques1,2. The technique is performed as follows. (1) Imaging is reviewed and preoperative planning is performed. (2) The patient is positioned in the lateral decubitus position with the operative extremity placed over a bolster. (3) A longitudinal posterior skin incision is centered just medial or lateral to the tip of the olecranon. Full-thickness skin flaps are raised medially and laterally. (4) The ulnar nerve is identified and mobilized for later anterior subcutaneous transposition. (5) An OO is performed at the non-articular "bare area" of the trochlear notch with an oscillating saw and completed with an osteotome. (6) Open reduction and internal fixation of the distal humerus is performed. (7) The osteotomy fragment is reduced, and a precontoured plate is applied. (8) A small longitudinal slit in the distal triceps over the proximal edge of the plate decreases plate prominence and is repaired with suture. (9) The subcutaneous tissues and skin are closed in the usual manner. Alterative techniques include extra-articular OO, triceps splitting, triceps reflecting, and lateral para-olecranon combined with a medial approach. Multiple drill holes and a thin osteotome can help mitigate the kerf created by the oscillating saw. Alternative fixation methods include a predrilled 6.5-mm intramedullary screw, a tension band construct, suture fixation, or a one-third tubular plate. The OO technique provides improved exposure when compared with alternative techniques, enabling accurate reduction and fixation of distal humeral fractures1-3. Wilkinson and Stanley found that OO exposed the distal humeral articular surface to a greater degree than the triceps-splitting and triceps-reflecting approaches3. OO has not been associated with triceps weakness, unlike some of the alternative techniques2. The incidence of good-to-excellent outcomes is similar when comparing the techniques for exposure of intra-articular distal humeral fractures4. Osteotomies united in all patients in 2 reported series, totaling 84 cases1,2. Removal of symptomatic hardware used in OO fragment fixation can occur in a small subset of patients1,2. Provisionally size a precontoured plate and fix it on the olecranon to aid in later reduction and fracture fixation.The bare area is the desired position for the OO because of its natural lack of cartilage5,6. This non-articular bare area is located just distal to the deepest portion of the trochlear notch, approximately 2 to 2.5 cm distal to the olecranon tip5,6.An (apex-distal) chevron osteotomy angle of ∼130° will help to keep the osteotomy within the non-articular bare area6.Beginning on the dorsal surface of the ulna, directly posterior to the bare area, an oscillating saw is utilized to create a chevron osteotomy to subchondral bone, perpendicular to the long axis of the ulna5,6.The OO is completed by fracturing through the osteochondral surface, which leaves an irregular chondral cancellous surface that can accurately interdigitate. This facilitates later reduction and stability of the osteotomy.Anatomic articular reduction of the OO is not solely judged on the dorsal cortical bone because of the kerf removed by the saw blade. Instead, examination of the articular surface of the trochlear notch is the primary assessment of reduction.Placement of suture through the proximal portion of the plate aids in the repair of the longitudinal split of the distal triceps.Successful treatment of distal humeral fractures requires accurate reduction and rigid fixation aided by adequate exposure achieved through OO. ORIF = open reduction and internal fixationOT = occupational therapyHWR = hardware removalK-wire = Kirschner wireROM = range of motion.

Lateral epicondyle osteotomy approach vs. olecranon osteotomy approach: an anatomic study of cadavers.

Exposure of the articular surface is the key to successful open reduction and internal fixation treatment for coronal shear fractures of the distal humerus. The olecranon osteotomy approach has previously been described as one of the most effective exposure approaches. Nevertheless, this approach cannot expose the anterior trochlea, and it is impossible to reduce and fix the capitellum under direct vision. The purpose of this study was to compare the exposure of the articular surface of the distal humerus between the lateral epicondyle osteotomy approach (group L) and the olecranon osteotomy approach (group O). Each approach was performed on 8 freshly frozen upper limbs of adult cadavers. After each approach was completed, a 0.5-mm Kirschner wire is inserted along the edge to mark the visible part of the articular surface. Then, the soft tissue of each elbow is removed, and a surface-scanning system is used to create a digital 3-dimensional model. The visible part of the articular surface obtained by each surgical approach was mapped and quantified using markers created by Kirschner wires. The lateral epicondyle osteotomy approach and the olecranon osteotomy approach exposed 0.8±0.0 and 0.6±0.0 of the distal humeral articular surface (P<.001), 1.0±0.0 and 0.3±0.1 of the capitellum (P<.001), 0.6±0.0 and 0.7±0.0 of the trochlea (P<.001), 0.7±0.0 and 0.5±0.1 of the anterior trochlea (P<.001), and 0.5±0.0 and 1.0±0.0 of the posterior trochlea, respectively (P<.001). Compared with the olecranon osteotomy approach, the lateral epicondyle osteotomy approach could more fully expose the total articular surface of the distal humerus, capitellum, and anterior trochlea, but the olecranon osteotomy approach could more fully expose the trochlea and posterior trochlea.

A review of the surgical management of distal humerus fractures and nonunions: From fixation to arthroplasty

Distal humeral fractures in adults are challenging injuries. They often require surgical intervention in form of internal fixation or total elbow arthroplasty which is being increasingly used in physiologically elderly patients with comminuted fractures. Careful preoperative evaluation including type of fracture, quality of bone, pre-existing conditions and functional demand help in deciding optimal treatment. CT scans including 2D and 3D reconstructions are almost mandatory in proper planning of the surgical treatment. In most cases with a healthy physiologically young patient, ORIF is the treatment of choice. Biomechanical studies have shown that parallel plating resists rotational deformity to a greater degree than 90/90 plating allowing supracondylar union. Accurate realignment of articular fragments and compression at the supracondylar area is key to the success of the internal fixation. Main cause of failure of fixation is the nonunion or malunion in the supracondylar area. The principles described by O'Driscoll et al. allow for rigid fixation of the distal articular fragments and compression at the supracondylar level which is vital to healing and the prevention of hardware failure, and nonunion. Olecranon osteotomy improves the expodure of distal humeral articular surface but has its own share of problems and should be avoided if possible. Irritation of ulnar nerve is a common complication so it should be isolated, kept under vision throughout and if necessary, transposed anteiriorly. Nonunion or malunion of supracondylar fractures can be treated by revision ORIF or total elbow arthroplasty (TEA). Supracondylar shortening, bone grafting and contracture release are important elements of treatment of nonunions.In unreconstructable distal humerus fractures, where open reduction and internal fixation is not possible due to the small size of the fragments, severe comminution and/or poor bone quality, TEA is the treatment of choice. Triceps can be left intact as the excision of fractured fragments usually provide enough space to carry out the operation. Sometimes, the decision to perform TEA is only made after exposing the fracture so the surgeon should be comfortable in performing TEA if ORIF is not possible; and necessary instruments and implants should be available on the shelf. In spite of satisfactory outcome, overall complication rate after TEA remains high and makes surgical efficiency and technical competence of utmost importance.

Lateral Elbow Overuse Injuries in Pediatric Female Gymnasts

Radial head stress fractures (RHSF) and capitellar osteochondritis dissecans (OCD) are rare. The purpose was to describe the clinical presentation of RHSF and compare demographic, radiographic, and clinical characteristics of pediatric gymnasts presenting with RHSF to those with capitellar OCD. A retrospective review of consecutive female gymnasts treated for either RHSF or capitellar OCD between 1/2014 and 2/2019 was performed. Gymnasts < 18 years old at the time of injury presenting with signs of a radial head stress fracture or with diagnostic features of capitellar OCD were included. Those with congenital abnormalities or prior ipsilateral elbow surgery were excluded. Patients were dichotomized into either the RHSF or OCD group. . Forty-five patients (9 with bilateral OCD, 1 with bilateral RHSF, and 3 with each lesion in alternate elbows), with 58 elbows (39 in OCD group; 19 in RHSF group), were included. Average age for all was 11.58 years (9-16 years), with no difference between groups (OCD: 11.47 vs RHSF: 11.78; p=0.34). No differences in height, weight, BMI, or laterality were noted. 94.74% of gymnasts presenting with RHSF were competing at a level 7 or higher compared with 66.67% of the OCD group (p=0.02). Compared to those with OCD, the RHSF group presented more acutely following symptom onset (p=0.014), reported more pain with valgus stress (p<0.001), and concurrent medial elbow pain than those with OCD (p<0.01). The RHSF group demonstrated smaller distal humeral width and decreased height of the proximal radial epiphysis, as well as increased valgus angulation of the radial neck shaft angles and distal humeral articular surface (p<0.05). (Table I) Gymnasts competing at a high competitive level and presenting more acutely may be at risk for RHSF. Additionally, differing anatomy in the lateral elbow may be a predisposing risk factor for RHSF and merits further investigation.

Surgical Elbow Dislocation Approach to the Distal Humerus for Apparent Capitellar and Lateral Condyle Fractures in Adults

Access to fractures of the distal humeral capitellum, trochlea, and lateral condyle is difficult through traditional approaches due to limited anterior articular exposure for direct reduction and fixation. The purpose of this study is to evaluate the relative articular exposure of a surgical dislocation (SD) approach to the distal humerus compared with olecranon osteotomy (OO). Eight paired elbows from 4 cadavers underwent either SD or OO approach. Methylene blue staining demarcated visualized articular surface before disarticulation of the elbows. The main outcome measures were average visualized total distal humeral articular surface and anterior and posterior surface, and capitellar surface relative to the total surfaces was compared for each surgical approach using unpaired parametric t-tests. Intraclass correlation between raters was 0.995. The median exposed articular surface for SD and OO approaches was 90.0% and 62.8%, respectively. The overall exposure was significantly greater for the dislocation technique (P = 0.0003). With respect to specific regions of the distal humeral articular surface, SD allowed significantly greater visualization of the anterior surface (95.9% vs. 48.9%, P < 0.0001) and capitellum (100% vs. 40.4%, P < 0.0001). The surgical elbow dislocation approach to the distal humerus permits near total exposure of the anterior articular surface and the entire capitellum. Our data support this approach for anterior articular fractures of the distal humerus, to include those fractures that extend to the medial surface of the trochlea.

Lateral Elbow Overuse Injuries in Pediatric Female Gymnasts: A Comparison of Radial Head Stress Fractures and Capitellar OCD

Objectives:Radial head stress fractures (RHSF) and capitellar osteochondritis dissecans (OCD) are rare and may be seen in pediatric gymnasts. Clinical and radiographic factors correlating with these differential lesions are unclear. To describe the clinical presentation of RHSF and compare the demographic, radiographic, and clinical characteristics of elbows in pediatric gymnasts presenting with RHSF to those presenting with OCD of the capitellum.Methods:An IRB-approved retrospective review of consecutive female gymnasts treated within a pediatric sports medicine practice for either RHSF or capitellar OCD over a 5-year period (1/2014-2/2019) was performed. Gymnasts <18 years old at the time of injury presenting with signs of a radial head stress fracture (Salter-Harris III or IV) or with diagnostic features of capitellar OCD were included. Those with congenital anatomic elbow abnormalities or prior ipsilateral elbow surgery were excluded. Patients were dichotomized into either the RHSF or OCD group; and demographic, radiographic, and clinical characteristics were compared. Statistical analysis was performed using a Mann-Whitney test for continuous variables and a chi-square test for categorical variables.Results:Forty-five patients (9 with bilateral OCD, 1 with bilateral RHSF, and 3 with each lesion in alternate elbows), contributing 58 elbows, met inclusion criteria. Thirty-nine elbows in the OCD group and 19 elbows in the RHSF group were studied. Average age for all gymnasts was 11.58 years (9-16 years), with no difference between groups (OCD: 11.47 vs RHSF: 11.78; p=0.34). No differences in height, weight, BMI, or laterality were noted. Gymnasts presenting with RHSF were competing at a higher level than those with OCD, with 94.74% of RHSF group competing at level 7 or greater compared to 66.67% of OCD patients (p=0.02).Compared to those with OCD, the RHSF group presented more acutely following onset of symptoms (p=0.014), reported significantly more pain with valgus stress (p<0.001), and concurrent medial elbow pain than those with OCD (p<0.01).The RHSF group demonstrated significantly smaller distal humeral width and decreased height of the proximal radial epiphysis, as well as increased valgus angulation of the radial neck shaft angles and distal humeral articular surface (p<0.05). No differences in olecranon or medial epicondyle hypertrophy, or avulsive changes were identified. (Table I)Conclusion:Gymnasts competing at a high competitive level and presenting more acutely may be at risk for RHSF. Additionally, differing anatomy in the lateral elbow may be a predisposing risk factor for RHSF as opposed to OCD and merits further investigation.

PEDIATRIC ELBOW COLLATERAL AND ANNULAR LIGAMENT ANATOMY: A CT-BASED CADAVERIC STUDY

Background:The medial and lateral ligamentous complexes of the elbow provide static restraint to the elbow and serve as important components of posteromedial and posterolateral rotatory instability. Many collateral ligament and medial epicondylar injuries require surgical repair in those with open physes. Little is known about the anatomy of the pediatric elbow and the relationship between these ligaments and physes. Purpose: To evaluate the anterior bundle of the medial collateral ligament complex, lateral ulnar collateral ligament, annular ligament, and relationships to the joint surfaces and physes.Methods:Two cadaveric elbows from a 3 year-old donor were dissected. Collateral and annular ligaments were isolated and left intact at their osseous attachment. Pins were placed at the origins and insertions and CT scans were used to establish precise anatomic relationships. All dissections and measurements were performed by a single orthopedic surgeon with specialization in pediatric sports medicine.Results:The MUCL origin was a mean 4.10 mm distal and anterior to the medial epicondyle, 10.09 mm from the distal humeral articular surface, and 9.01 mm distal to the medial physis. The distal insertion of the MUCL spanned a mean 3.09 mm and was posterior and medial to the sublime tubercle. In the longitudinal axis, the MUCL insertion footprint spanned the tubercle. The origin was a mean 1.20 mm proximal to the sublime tubercle and the distal extent averaged 2.53 mm distal to the tubercle. The center of the MUCL insertional footprint was 0.38 mm distal to the tubercle. The center of the MUCL was 3.87 mm from the olecranon articular surface.The annular ligament had consistent medial and lateral attachments to the ulna. Distance from the annular ligament attachments to the tip of the coronoid averaged 4.6 mm (4.46 & 4.74 lateral and medial for left; 4.80 & 5.27 lateral and medial for right).The LUCL origin was distal and anterior to the lateral epicondyle. It was 3.43 mm from the lateral epicondyle, 7.51 mm from the articular surface and 0.74 mm distal to the physis.Conclusions:This study is the first to describe anatomy of the elbow collateral and annular ligaments in pediatric cadaveric specimens, through a reliable, CT-based identification method. Knowledge of the precise ligamentous attachments and relationships to the physis and to the joint surface is important for reconstructive procedures. A better understanding of these relationships may assist with surgical planning that preserves adjacent physeal growth regions.

LATERAL ELBOW OVERUSE INJURIES IN PEDIATRIC FEMALE GYMNASTS: A COMPARISON OF RADIAL HEAD STRESS FRACTURES AND CAPITELLAR OCD

Background:Radial head stress fractures (RHSF) and capitellar osteochondritis dissecans (OCD) are rare and may be seen in pediatric gymnasts. Clinical and radiographic factors correlating with these differential lesions are unclear.Purpose:To describe the clinical presetantion of RHSF and compare the demographic, radiographic, and clinical characteristics of elbows in pediatric gymnasts presenting with RHSF to those presenting with OCD of the capitellum.Methods:An IRB-approved retrospective review of consecutive female gymnasts treated within a pediatric sports medicine practice for either RHSF or capitellar OCD over a 5-year period (1/2014-2/2019) was performed. Gymnasts <18 years old at the time of injury presenting with signs of a radial head stress fracture (Salter-Harris III or IV) or with diagnostic features of capitellar OCD were included. Those with congenital anatomic elbow abnormalities or prior ipsilateral elbow surgery were excluded. Patients were dichotomized into either the RHSF or OCD group; and demographic, radiographic, and clinical characteristics were compared. Statistical analysis was performed using a Mann-Whitney test for continuous variables and a chi-square test for categorical variables.Results:Forty-five patients (9 with bilateral OCD, 1 with bilateral RHSF, and 3 with each lesion in alternate elbows), contributing 58 elbows, met inclusion criteria. Thirty-nine elbows in the OCD group and 19 elbows in the RHSF group were studied. Average age for all gymnasts was 11.58 years (9-16 years), with no difference between groups (OCD: 11.47 vs RHSF: 11.78; p=0.34). No differences in height, weight, BMI, or laterality were noted. Gymnasts presenting with RHSF were competing at a higher level than those with OCD, with 94.74% of RHSF group competing at level 7 or greater compared to 66.67% of OCD patients (p=0.02).Compared to those with OCD, the RHSF group presented more acutely following onset of symptoms (p=0.014), reported significantly more pain with valgus stress (p<0.001), and concurrent medial elbow pain than those with OCD (p<0.01).The RHSF group demonstrated significantly smaller distal humeral width and decreased height of the proximal radial epiphysis, as well as increased valgus angulation of the radial neck shaft angles and distal humeral articular surface (p<0.05). No differences in olecranon or medial epicondyle hypertrophy, or avulsive changes were identified. (Table I)Conclusion:Gymnasts competing at a high competitive level and presenting more acutely may be at risk for RHSF. Additionally, differing anatomy in the lateral elbow may be a predisposing risk factor for RHSF as opposed to OCD and merits further investigation.Table 1.Comparison of activity, clinical, and radiographic charcteristics in pediatric female gymnast to with radial head stress fractures (RHSF) and osteochondritis dissecans of the capitellum (OCD).

A Comprehensive Coronal and Axial Bone Dimension and Cartilage Thickness Evaluation of the Distal Humerus: Age and Sex Differences.

There are limited data on bone dimension and cartilage thickness of the distal humeral articular surface. This study aimed to evaluate sex- and age-related bone dimension and cartilage thickness differences and assess the effect of cartilage thickness on distal humeral shape. Elbow magnetic resonance images of 180 healthy participants were evaluated. Cartilage thicknesses of the trochlea and capitellum were measured at 19 points using coronal and axial images. In addition, bone diameters were measured from the flexion-extension axis to the 19 points on the coronal and axial magnetic resonance images. Sex differences were evaluated, and the correlation between age and measurement parameters was assessed. Significant sex differences regarding the diameters of the axial trochlear bone, coronal lateral trochlear bone, and medial capitellar bone, cartilage thickness at the apex of the lateral trochlear ridge in the axial and coronal plane and at the most lateral point of the capitellar articular surface in the axial plane were observed. A negative correlation was observed between age and axial plane trochlear bone dimensions and between age and coronal plane lateral trochlear and medial capitellar bone dimensions. No significant correlation was found between cartilage thickness and bone dimensions. Bone dimension and cartilage thickness at the distal humerus vary according to sex and age. The data could be used in the donor site selection and graft preparation while osteochondral autograft transfer and allograft transplantation, and in the development of gender-compatible hemiarthroplasty implants.

Surgical Treatment of Intra-Articular Distal Humeral Fractures by using a Combined Medial and Lateral Approach: An Anatomic Study.

ObjectiveTo determine the visible size of the distal humeral articular surface by using a novel combined medial‐lateral approach as an alternative method of surgical treatment for intra‐articular distal humeral fractures.MethodsIn this anatomical study, 12 adult fresh‐frozen cadaveric elbows were randomly divided into a medial‐lateral group and an olecranon osteotomy group, with 6 in each group. In the medial‐lateral group, a medial approach was first used, and then a lateral approach. The sizes of the distal humeral articular surface exposed by each incision and the joined size were measured and calculated. In the olecranon osteotomy group, a posterior olecranon osteotomy approach was applied, and the maximal visible sizes of the articular surface were marked and calculated. Ratios of the maximal sizes of the distal humeral articular surface of the two approaches were compared.ResultsIn the medial‐lateral group, the medial approach could expose 2/5 of the medial trochlea and 1/3 of the capitellum, while the mean visible size of the distal humeral articular surface was 6.8 cm2, 34.8% of the entire surface; the lateral approach can expose 3/7 of the capitellum and 1/4 of the medial trochlea, while the mean visible size of the distal humeral articular surface was 6.7 cm2, 33.9% of the whole surface; for the combined medial‐lateral approach, the mean scope exposed of the medial and lateral visible articular surface was 38.2% and 43.1%, respectively. Meanwhile, in the olecranon osteotomy group, the posterior olecranon osteotomy was found to expose most of the posterior distal humeral articular surface, except for 1/3 of the anterior trochlea and 1/4 of the anterior capitellum, and the visible range of articular surface was 65.3%. The combined medial‐lateral approach exposed 9.2 cm2 in total, 46.9% of the whole distal humeral articular surface, which averaged 19.6 cm2. However, the visible size of the distal humeral articular surface for the olecranon osteotomy approach was 13.7 cm2, 63.1% of the entire distal humeral articular surface, which averaged 21.3 cm2. There was a significant difference observed between the medial‐lateral group (46.9%) and the olecranon osteotomy group (63.1%) for the maximal visible size of the distal humeral articular surface (t = 7.201, P = 0.001).ConclusionsThe combined medial‐lateral approach can expose 46.9% of the distal humeral articular surface, concentrating on the anterior part, so it can be recommended to treat intra‐articular fractures with a simple pattern in the posterior with the anterior side of the distal humerus less comminuted.

Comparison of the Visible Articular Surface between the Lateral Para-Olecranon Approach and Two Other Common Posterior Approaches for Distal Humeral Fracture: an Anatomical Study

Purpose To quantify the visible area of the articular surface of the distal humerus exposed by the lateral para-olecranon (LPO) approach and to compare this with the bilaterotricipital (BT) and olecranon osteotomy (OO) approaches. Methods We examined 12 elbows from 6 fresh cadavers (mean age, 93.5 years; range, 90–99 years; 3 men and 3 women). Elbows on one side of the cadavers underwent the LPO approach. The opposite elbows underwent the BT approach followed by the OO approach. Macroscopically observable articular cartilage was coated with synthetic silicone resin paint under direct vision. The dissected bone was fixed on the table and photographs of the distal humerus were taken from anteriorly and posteriorly. The color-coded areas projected on 2 planes were quantified using digital photography and computer analysis software. Results Proportions of the total visible area, summation of the anterior and posterior visible articular areas, were 25.3% ± 2.2% for the BT procedure, 46.4% ± 8.4% for the LPO procedure, and 58.5% ± 5.7% for the OO procedure, showing significant differences among the 3 procedures. The LPO procedure achieves better exposure of the posterior articular surface than the BT procedure, but the LPO procedure had limitations in the anterior visible area compared with the OO procedure. In particular, direct vision of the humeral trochlea was restricted by the presence of the olecranon. Conclusions The LPO approach has improved visualization of the distal humeral articular surface compared with the BT approach but not as good as that achieved with the OO approach. Clinical relevance The LPO approach is applicable to cases of AO type C1 and C2 distal humeral fractures and some cases of type C3 fracture, excluding those accompanied by complex fractures in the trochlea of the humerus. It is important to evaluate the fracture line of the humeral trochlea in preoperative computed tomography to determine whether to use the LPO or OO approach for AO type C3 fracture.

Surgical exposures of the distal humeral fractures: An anatomical study of the anterior, posterior, medial and lateral approaches

PurposeExposure of the articular surface is the key to the successful treatment of intra-articular fractures of distal humerus. Anterior, posterior olecranon osteotomy as well as medial and lateral approaches are the four main approaches to the elbow. The aim of this study was to compare the exposure of distal articular surfaces of these surgical approaches. MethodsTwelve cadavers were used in this study. Each approach was performed on six elbows according to previously published procedures. After completion of each approach, the exposed articular surfaces were marked by inserting 0.5 mm K-wires along the margins. The elbow was then disarticulated and the exposed articular surfaces were painted. The distal humeral articular surfaces were then closely wrapped using a piece of fibre-glass screen net with meshes. The exposed articular surfaces and the total articular surfaces were calculated by counting the number of meshes, respectively. ResultsThe average percentages of the exposed articular surfaces for the anterior, posterior olecranon osteotomy, medial and lateral approaches were 45.7% ± 2.0%, 53.9% ± 7.1%, 20.6% ± 4.9% and 28.5% ± 6.3%, respectively. ConclusionThe anterior and posterior approaches provide greater exposures of distal humeral articular surface than the medial and lateral ones in the treatment of distal humeral fractures.

Biomechanical Comparison of Olecranon Sled Versus Intramedullary Screw Tension Banding for Olecranon Osteotomies.

Background:Olecranon osteotomies are frequently performed to gain access to the distal humeral articular surface. Repair of the osteotomy or fixation of a simple 2-part olecranon fracture with traditional tension band construct is often plagued by complication. Proximal migration and irritation attributed to hardware are common complications of the standard construct of an intramedullary screw with tension band and are causes for reoperation.Purpose:To compare the biomechanical performance, time of implant, and prominence of an intramedullary screw and tension band construct with that of a newer low-profile continuous loop tension band (Olecranon Sled) construct in an olecranon osteotomy model.Study Design:Controlled laboratory study.Methods:Chevron osteotomies were created in 6 matched pairs of fresh-frozen human elbows (mean age, 66 ± 16 years). Each matched pair was then randomly divided into 1 of 2 groups: fixation with a screw and tension band construct or the Olecranon Sled. Bone mineral density, implant prominence, and time for implantation were recorded. Following olecranon fixation, each specimen underwent cyclic loading of 0 to 10 N for 100 cycles (to simulate unresisted active range of motion) and then 0 to 500 N for 500 cycles (to simulate pushing up from a chair) to measure for any displacement at the osteotomy site. The constructs were then loaded to failure and compared.Results:No differences were found in bone mineral density between the 2 groups (P = .290). When measured from the tip of the olecranon, the continuous loop tension band had a medial prominence of only 3.57 ± 0.4 mm, as opposed to the intramedullary screw fixation of 7.288 ± 0.762 mm (P = .027). Total time of implantation, including osteotomy preparation, was a mean 155 seconds shorter with the Olecranon Sled versus the traditional tension band (P < .05). Because of the fracture of 1 specimen during cyclic loading, it and its matched counterpart were excluded, and only 5 matched pairs were analyzed for displacement and load to failure. There were no significant differences between groups in load to failure or displacement during cyclic loading (P > .05).Conclusion:The Olecranon Sled device was found to have no difference in biomechanical strength from that of the standard intramedullary screw with tension band construct. The Olecranon Sled was also found to be significantly less prominent while being faster to implant than the intramedullary screw.Clinical Relevance:Evaluating an alternative option to the standard tension band construct is important for patients with olecranon fractures or osteotomies, as standard techniques have been fraught with hardware issues and need for revision surgery.

Effectiveness comparison between the paratricipital approach and the chevron olecranon V osteotomy approach in the treatment of type C3 distal humeral fractures

To compare the effectiveness between paratricipital approach and chevron olecranon V osteotomy approach for the treatment of type C3 (AO/OTA) distal humeral fractures and investigate the details of operation. Between April 2010 and September 2016, 36 type C3 (AO/OTA) distal humeral fractures were treated with open reduction and bicolumnar orthogonal locking plating fixation by paratricipital approach and chevron olecranon V osteotomy approach respectively. The patients were divided into 2 groups by approach, there were 17 cases in paratricipital group (group A) and the bicolumns and distal humeral joint surface were exposed by traction of triceps and olecranon, and the distal humeral joint surface of the 19 cases in chevron olecranon V osteotomy group (group B) were exposed by osteotomy of the olecranon and reversing of triceps. There was no significant difference in gender, age, dominant side, interval between injury and surgery, causes of injury between 2 groups ( P>0.05). Patients were followed up, the postoperative range of motion of elbow joint, strength, pain, and stability in 2 groups were documented and compared; the elbow joint function was evaluated according to Mayo elbow performance score (MEPS). The operation time of group A [(115.0±10.4) minutes] was less than that of group B [(121.0±12.3) minutes], but there was no significant difference ( t=–1.580, P=0.123). All patients in 2 groups got over 1 year follow-up and there was no significant difference of the follow-up time between 2 groups ( t=–0.843, P=0.405). There was 1 case of heterotopic ossification in each group; 1 case of incision infection in group A and 1 case of incision superficial infection in group B, and were cured after 2 weeks of intravenous antibiotics administration. There was no other operative complications in the 2 groups. At 3 months after operation, all the distal humerus healed. At last follow-up, the elbow flexion extension range of groups A and B were (102.0±12.6)° and (99.5±10.1)° respectively, showing no significant difference ( t=–0.681, P=0.501). The MEPS scores of groups A and B were 82.9±7.3 and 81.3±7.2 respectively, showing no significant difference ( t=0.670, P=0.507); and the evaluation grade also showed no significant difference between 2 groups ( Z=–0.442, P=0.659). By paratricipital approach and proper traction of the olecranon, the distal humeral articular surface can be exposed in the operation of type C3 distal humeral fractures, followed with same stable fixation after reduction, the effectiveness is equal to by chevron olecranon V osteotomy approach.

Triceps-sparing extra-articular step-cut olecranon osteotomy for distal humeral fractures: an anatomic study

This anatomic study investigated the distal humeral articular surface exposure achievable through a triceps-sparing oblique extra-articular osteotomy of the olecranon with a step-cut modification compared with the anconeus flap transolecranon apex distal chevron osteotomy. In addition, the bone contact surface areas of the osteotomized surfaces after transolecranon and extra-articular osteotomies were compared. Seven pairs of fresh adult cadaveric elbow joints were examined. Each of the right elbows underwent triceps-sparing extra-articular step-cut olecranon osteotomy (SCOOT) with an anconeus flap, and the left elbows underwent the anconeus flap transolecranon apex distal chevron osteotomies (CO). The articular surface exposed by each of the osteotomy techniques was then digitally analyzed using a 3-dimensional measurement system. The bone contact surface area of the osteotomized surfaces was also assessed. The percentage of total joint exposed by the SCOOT group was less than the CO group (SCOOT: 64% ± 3% vs. CO: 73% ± 3%; P = .002). There was significantly greater bone contact surface area of the osteotomized surfaces in the SCOOT group compared with the CO group (SCOOT: 1172 ± 251 mm2 vs. CO: 457 ± 133 mm2; P = .002). The triceps SCOOT procedure with an anconeus flap provides excellent distal humeral articular surface exposure with the added benefit of a substantially increased (2.6-times) bone contact surface area of the osteotomized surfaces.

Radiographic comparison of adolescent athletes with elbow osteochondritis dissecans to ulnar collateral ligament injuries and controls

There are excellent data supporting recommendations to prevent elbow injuries (osteochondritis dissecans [OCD] and ulnar collateral ligament [UCL] injuries), such as pitch count and pitch type in baseball, but anatomic risk factors have not been thoroughly examined. This study aimed to evaluate radiographic measurements in adolescents with elbow OCD lesions or UCL injuries and controls. We retrospectively identified adolescent patients between 2011 and 2016 with isolated capitellum OCD, UCL tear, or normal elbows based on magnetic resonance imaging. Nineteen patients (mean age, 13.5 years) had isolated OCD defects of the capitellum, 8 patients (mean age, 16.9 years) had isolated UCL complete tear, and the remaining 16 patients (mean age, 14.6 years) were normal controls. Radiographic measurements from corresponding anterior-posterior elbow radiographs were taken, including carrying angle, distal humeral articular surface angle, and radial neck-shaft angle. On the lateral radiograph, anterior angulation of the articular surface of distal humerus was measured. Significant differences were observed in carrying angle between controls (15.7°) and OCD patients (11.6°; P = .03) as well as between controls and UCL patients (10.3°, P = .02), with the OCD and UCL patients tending to be in more varus. Significant differences were also found between controls (88.5°) and OCD patients (93.6°; P = .01) and between controls and UCL patients (93.3°; P = .03) in distal humeral articular surface angle, with OCD and UCL patients with increased valgus at the distal humerus articular surface. There were no significant differences between groups in radial neck-shaft angle or anterior angulation of articular surface of distal humerus. Patients with OCD and UCL injuries have anatomic differences compared with normal controls that can be measured radiographically.

Modified anconeus flap approach for intercondylar humerus fractures

Objective To report a new surgical approach(modified anconeus flap approach)in which the anconeus and part of triceps are reflected in the treatment of distal intercondylar humerus fracture(AO type C). Methods To design the modified anconeus flap approach, the anatomy of the distal tendon of the triceps brachii and the anconeus was studied using 15 cadaveric adult specimens(30 sides). The new surgical approach was compared with the triceps-reflecting anconeus pedicle(TRAP)approach in terms of the area of exposure at the distal humeral articular surface. Furthermore, the new surgical approach was applied in 16 patients who had been treated for intercondylar humerus fracture(AO type C)from May 2005 to May 2013. The clinical outcomes were evaluated using the Mayo elbow performance score(MEPS)and Broberg-Morrey scoring systems. Results The blood supply and innervation of the anconeus was interrupted minimally during incision along the radical edge of triceps tendon. The area of exposure at the distal humeral articular surface provided by the part triceps and anconeus reflecting approach and the medial humerus approach was 42. 66% ±0. 03% at the elbow flexion from 0° to 50°. This was significantly smaller than that provided by the TRAP approach(46. 11% ± 0. 03%)(P< 0. 05). Of the 16 patients, 15 obtained complete follow-ups from 6 months to 4 years(average, 16. 5 months). The mean MEPS at the last follow-up was 90. 5 points(range, from 82 to 93 points), with 10 excellent and 4 good cases and one poor case. The Broberg & Morrey score system showed 11 patients with no articular cartilage degeneration(level-0), 3 patients with level-1 degeneration, and 2 patients with level-2 degeneration. Conclusion The modified anconeus flap approach proposed in the present study provides clear surgical vision and needs no olecranon osteotomy or olecranon dissection or ablation of the major triceps brachii tendon for intercondylar humerus fractures, thereby leading to early active motion and satisfactory clinical outcomes. Key words: Humeral fractures; Autopsy; Therapies, investigational; Surgical approach

Applied anatomical study of the modified anconeus flap approach.

Conventional surgical therapy for an intercondylar humerus fracture might result in multiple potential complications. Our study was conducted to evaluate the modified anconeus flap approach by adequately exposing the distal humeral articular surface, avoiding osteotomy of the olecranon and transection of the main part of the triceps brachial tendon from the olecranon. Preparations of 20 upper limb specimens from adult cadavers were used in this study. We investigated the anatomical features of the distal tendon of the triceps brachii. Then, we designed a modified anconeus flap approach in cadaver specimens combined with the medial paratricipital approach, and we compared the extent of exposure of the distal humeral articular surface between the triceps-reflecting anconeus pedicle approach and this modified approach. The downward neurovascular bundles supplying the anconeus were located far from the intramuscular tendon of the triceps brachii. In addition, the medial head of the triceps was continuous with the anconeus near the lateral epicondyle of the humerus. These anatomical properties could assist in reducing adverse events in surgery. The percentage of the exposed humerus distal articular surface was 42.7% by applying the modified anconeus flap approach combined with the medial paratricipital approach. The modified anconeus flap approach can overcome the shortcomings of osteotomy or triceps transverse and fulfill reduction and internal fixation of most distal humerus intercondylar fractures. The present study has demonstrated a new approach for adequately exposing the distal humeral articular surface during surgery for an intercondylar humerus fracture. With this modified approach, osteotomy of the olecranon and the separation or transection of the main part of the triceps brachial tendon from the olecranon are not necessarily required. Therefore, we suggest that this novel approach could be applied as the primary surgical approach in intercondylar humerus fracture surgeries if the surgeons are familiar with the regional features of distal tendon of the triceps brachii and anconeus.

Distal Humeral Fractures in Adults

Distal humeral fractures in adults are relatively uncommon injuries that require operative intervention in the majority of cases. Dual plate fixation, with placement of a separate strong plate on each column and orientation of the plates either at 90° or 180° to each other, is indicated for all adult fractures involving both columns of the distal part of the humerus. Acute total elbow arthroplasty is the preferred treatment for elderly patients with a displaced, comminuted, intra-articular distal humeral fracture that is not amenable to stable internal fixation. Displaced coronal shear fractures of the distal humeral articular surface require operative fixation, most typically via a lateral approach.

Effect of coronal shear fractures of the distal humerus on elbow kinematics and stability

Coronal shear fractures of the distal humerus can include some or all of the cartilaginous and bony surface. Fixation is preferred, but severe comminution, nonunion, and avascular necrosis may mandate excision. The amount of distal humerus that is safe to excise is unknown. This study examined the effect of excision of the capitellum and trochlea on elbow kinematics and stability with intact collateral ligaments. Eight cadaveric arms were mounted in an upper extremity joint testing system. Electromagnetic receivers on the radius and ulna enabled quantification of ulnohumeral and radiocapitellar kinematics. The distal humeral articular surface was sequentially excised to replicate clinically relevant coronal shear fractures, leaving the collateral ligaments undisturbed. The arms underwent simulated active flexion in vertical and valgus-loaded positions, and passive forearm rotation in the vertical position. In the vertical position, sequential excision of the articular surface increased valgus angulation during active flexion (P < or = .04), and excision of the entire articular surface increased ulnar external rotation compared to the intact elbow (P < or = .02). In the valgus position, excisions involving the trochlea increased valgus angulation for active flexion (P < or = .04). The radial head moved distal, posterior, and medial on the capitellum with some or all of the trochlea excised (P < or = .02). While the capitellum alone does not contribute to elbow stability, the trochlea has an important role. Excision of the trochlea resulted in multiplanar instability of the ulnohumeral and radiocapitellar joints. Therefore, excision of an irreparable capitellum fracture may be considered if collateral ligaments are intact, while excision of some or all of the trochlea may not.