Humeral Plate Research Articles

Early results for treatment of two- and three-part fractures of the proximal humerus using Contours PHP (proximal humeral plate).

Background and aim of the work: The management of displaced 2- and 3-part fractures of the proximal humerus is controversial, both in younger and in elderly patients. The purpose of this paper is to evaluate the functional results of the Contours Proximal Humerus Plate (OrthofixR, Bussolengo,Verona, Italy), for the treatment of displaced 2- and 3-part fractures of the proximal humerus. Methods: We retrospectively reviewed 55 patients with proximal humerus fractures, who underwent osteosynthesis with Contours Proximal Humerus Plate from December 2011 to March 2015. We had 21 patients with 2-part fractures and with an average age of 67.1 years and 34 patients with 3-part fractures, with average age of 63.6 years. Results: The average union time was 3 months. The mean Constant score was 67 for 2-part fracture group and 64.9 for 3-part fracture group. The difference was not statistically significant (p = 0.18). The overall complication rate was 14.5 %. Six patients underwent additional surgery (10.9%). Conclusions: The most frequent major complication was secondary loss of reduction following varus collapse of the fracture (2 cases). In these patients, there was loss of medial hinge integrity due to impaction and osteoporosis. The placement of the main locking screw in the calcar area to provide inferomedial support is the rational of the Contours Proximal Humerus Plate. Osteosynthesis with Contours Proximal Humerus Plate is a safe system for treating displaced 2- and 3-part fractures of the proximal humerus, with good functional results and complication rates comparable to those reported in the literature. (www.actabiomedica.it)

Efficacy of zoledronic acid combined with locking proximal humeral plate in treatment of proximal humeral osteoporotic fractures

Objective To evaluate the clinical effect of zoledronic acid combined with locking proximal humeral plate in the treatment of proximal humeral osteoporotic fractures in elderly patients. Methods A retrospective analysis was made on the data of 30 elderly patients with complete follow-up after surgically treated proximal humeral osteoporotic fractures between January 2012 and May 2015. There were 12 male and 18 female patients, with age range of 60-86 years (mean, 69.5 years). According to the Neer classification system, five patients had two-part fractures, nineteen three-part fractures and six four-part fractures. No open injury or combined vascular and nerve injuries occurred. All patients had open reduction and internal fixation with locking proximal humeral plate. The patients were divided into basic treatment group (anti-osteoporosis therapy with oral calcium carbonate and calcitriol was administered after operation, n=14) and combined treatment group (intravenous zoledronic acid was used after operation in addition to the basic treatment, n=16) according to the random number table. Neer score of the shoulder joint was recorded at admission and at postoperative 1 year. Bone healing and subsequent refracture were assessed with X-ray postoperatively. Dural energy X-ray absorptiomery (DXA) was used to detect bone mineral density of the left hip at admission and one year after operation. Refracture was recorded within one year after operation. Results All patients showed bone union without the presence of delayed union or non-union.Bone union time was (17.32±3.41) weeks in combined treatment group and (18.24±3.74) weeks in basic treatment group (P>0.05). After one year, shoulder function score presented the good-excellent rate of 81% in combined treatment group and 79% in basic treatment group (P>0.05). Improved bone mineral density was seen in both groups one year after operation [control group: neck (0.651±0.070)g/cm2, Ward area (0.477±0.049)g/cm2, greater trochanter (0.569±0.073)g/cm2; combined treatment group: neck (0.631±0.075)g/cm2, Ward area (0.498±0.050) g/cm2, greater trochanter(0.576±0.069)g/cm2], but the change was only significant in combined treatment group (P<0.05). There was one patient with Colles fracture of the left distal radius, one T12 vertebral compression fracture and one L3 vertebral compression fracture in basic treatment group, but no new fractures occurred in combined treatment group. Conclusion Zoledronic acid combined with locking proximal humeral plate in the treatment of proximal humeral osteoporotic fractures can restore shoulder function, significantly increase bone mineral density, and decrease incidence of subsequent fractures. Key words: Osteoporotic fractures; Humeral fractures; Phosphonic acids; Locking plate

Evaluation of the fossil fish-specific diversity in a chadian continental assemblage: Exploration of morphological continuous variation in Synodontis (Ostariophysi, Siluriformes).

In the fossil record, the quantification of continuous morphological variation has become a central issue when dealing with species identification and speciation. In this context, fossil taxa with living representatives hold great promise, because of the potential to characterise patterns of intraspecific morphological variation in extant species prior to any interpretation in the fossil record. The vast majority of catfish families fulfil this prerequisite, as most of them are represented by extant genera. However, although they constitute a major fish group in terms of distribution, and ecological and taxonomic diversity, the quantitative study of their past morphological variation has been neglected, as fossil specimens are generally identified based on the scarcest remains, that is, complete neurocrania that bear discrete characters. Consequently, a part of freshwater catfish history is unprospected and unknown. In this study, we explored the morphological continuous variation of the humeral plate shape in Synodontis catfishes using Elliptic Fourier Analysis (EFA), and compared extant members and fossil counterparts. We analysed 153 extant specimens of 11 Synodontis species present in the Chad basin, in addition to 23 fossil specimens from the Chadian fossiliferous area of Toros Menalla which is dated around 7 Ma. This highly speciose genus, which is one of the most diversified in Africa, exhibits a rich fossil record with several hundred remains mostly identified as Synodontis sp. The analysis of the outline of the humeral plate reveals that some living morphological types were already represented in the Chad Basin 7 My ago, and allows for the discovery of extinct species. Beside illuminating the complex Neogene evolutionary history of Synodontis, these results underline the interest in the ability of isolated remains to reconstruct a past dynamic history and to validate the relevance of EFA as a tool to explore specific diversity through time. J. Morphol. 277:1486-1496, 2016. © 2016 Wiley Periodicals, Inc.

Hertel 7 fracture of the humeral head. Can two different fixation systems (Diphos/PHP) lead to different outcomes? A retrospective study

ObjectiveTo compare clinical outcomes and complication rates in the medium-to-long-term follow-up of Hertel 7 humeral head fractures treated with two different locking plates. Materials and MethodsA total of 52 patients with type 7 humeral head fracture (in accordance with Hertel classification) were enrolled retrospectively: 24 patients [4 male, 20 female; mean age (standard deviation [SD]): 68.9 (5.8) years] were treated with Diphos H plate (Group A) and 28 patients [6 male, 22 female; mean age (SD): 61.0 (7.5) years] with Proximal Humeral Plate (PHP; Group B). The mean follow-up periods were 25.6 and 18.9 months, respectively. Functional outcomes were assessed using the Constant score and Disabilities of the Arm, Shoulder and Hand (DASH) score; X-ray evaluation was also performed and complications were recorded. ResultsThe mean Constant score in the Diphos and PHP groups at follow-up were 75.6 (SD 13.4) and 78.9 (SD 12.8), respectively (p>0.05). The DASH score was similar in both groups (Diphos: 18.6, range 0-51.5; PHP: 16.8, range 0-47.8) (p>0.05). In our series, 9.6% of patients had complications; these included a case of aseptic non-union and a case of avascular necrosis of the humeral head in each group, and a secondary screw perforation in a patient treated with Diphos. ConclusionsIn patients with Hertel 7 proximal humeral fractures, Diphos and PHP lead to similar satisfactory functional outcomes and are associated with low complication rates; this confirms that both are useful implants for the treatment of this pattern of fracture.

Tibiotalocalcaneal arthrodesis by using proximal humeral locking plate

ObjectivesThe aim of this study was to evaluate the short-term clinical and radiological results of tibiotalocalcaneal arthrodesis (TTCA) with proximal humeral locking plate. Material and methodsEight patients (7 female, 1 male; average age 53 years (range: 24–67)) who underwent TTCA with proximal humeral locking plate between 2009 and 2011, were retrospectively evaluated with AOFAS hindfoot scale and Maryland foot score system. The mean follow up was 32.6 months (range: 23–54). ResultsComplete fusion was achieved in 7 patients. Soft tissue infection was observed in 2 patients and reflex sympathetic dystrophy in 3 patients. All patients recovered with medical treatment. At the final follow-up, mean AOFAS Hindfoot score was 60 (range: 41–81) and Maryland Foot Score was 67.8 (range: 41–85). The satisfactory rates of AOFAS and MFS were found as 12.5% (1/8) and 50% (4/8), respectively. One patient had an incomplete union with 5 degrees of heel varus deformity and 5 degrees of equinus deformity was observed in another. There were no implant failure or deformation of the plate during the follow-up period. ConclusionOur study suggests that proximal humeral plate may be an alternative for fixation in tibiotalocalcaneal fusion surgery.

Retrograde dynamic locked intramedullary nailing for aseptic supracondylar femoral nonunion after dynamic condylar screw treatment.

Supracondylar femoral nonunions after dynamic condylar screw (DCS) treatment are uncommon, and few studies have addressed an optimal treatment technique for this disorder. Re-insertion of a new plate may not be secure because of bony defects in the distal fragment, created by the lag screw of the DCS. Forty-two consecutive adult patients with 42 supracondylar femoral nonunions were treated with removal of the DCS, re-alignment of the knee axis, and insertion of a retrograde dynamic traditional femoral locked nail. When necessary, a humeral plate was augmented to reinforce rotational stability. A final group of 36 patients with 36 nonunions were followed for an average of 2.8years (range 1.1-6.2years). All nonunions healed with a union rate of 100%, and the average time to union was 4.2months (range 2.5-5.5months). Complications included two malunions. There were no instances of nonunion or deep infection. Satisfactory knee function among 36 patients improved from 8.2% preoperatively to 86.1% at the last follow-up (p<0.001). All 36 patients could walk without aids. The described technique may be an excellent alternative treatment for an aseptic supracondylar femoral nonunion after DCS treatment. The technique is not difficult, and the union rate and satisfactory rate are high.

Biomechanical effect of the configuration of screw hole style on locking plate fixation in proximal humerus fracture with a simulated gap: A finite element analysis

BackgroundLocking plate fixation for proximal humeral fractures is a commonly used device. Recently, plate breakages were continuously reported that the implants all have a mixture of holes allowing placement of both locking and non-locking screws (so-called combi plates). In commercialized proximal humeral plates, there still are two screw hole styles included “locking and dynamic holes separated” and “locking hole only” configurations. It is important to understand the biomechanical effect of different screw hole style on the stress distribution in bone plate. MethodsFinite element method was employed to conduct a computational investigation. Three proximal humeral plate models with different screw hole configurations were reconstructed depended upon an identical commercialized implant. A three-dimensional model of a humerus was created using process of thresholding based on the grayscale values of the CT scanning of an intact humerus. A “virtual” subcapital osteotomy was performed. Simulations were performed under an increasing axial load. The von Mises stresses around the screw holes of the plate shaft, the construct stiffness and the directional displacement within the fracture gap were calculated for comparison. ResultsThe mean value of the peak von Mises stresses around the screw holes in the plate shaft was the highest for combi hole design while it was smallest for the locking and dynamic holes separated design. The stiffness of the plate-bone construct was 15% higher in the locking screw only design (132.6N/mm) compared with the combi design (115.0N/mm), and it was 4% higher than the combi design for the locking and dynamic holes separated design (119.5N/mm). The displacement within the fracture gap was greatest in the combi hole design, whereas it was smallest for the locking hole only design. ConclusionsThe computed results provide a possible explanation for the breakages of combi plates revealed in clinical reports. The locking and dynamic holes separated design may be a better configuration to reduce the risk of plate fracture.

Treatment of Middle Third Humeral Shaft Fractures with Anteromedial Plate Osteosynthesis through an Anterolateral Approach.

Background: Treatment of humeral shaft fractures has been a subject of debate for many decades. Even though a large majority of humeral shaft fractures can be treated by non operative methods, few conditions like open fractures, polytrauma, ipsilateral humeral shaft and forearm fractures require surgical intervention. The goal of treatment of humeral shaft fractures is to establish union with an acceptable humeral alignment and to restore the patient to pre-injury level of function. The objective was to assess the incidence of radial nerve palsy, non-union and mean time required for in anteromedial plate osteosynthesis with anterolateral approach and also to measure the functional outcome of this procedure.Method: A prospective study was conducted in the Department of Orthopaedics, PESIMSR, Kuppam, Andhra Pradesh, from August 2012 to August 2015 with a total of 54 patients who were operated with anteromedial plate osteosynthesis were included in the study. Rodriguez- Merchan criteria was used to grade the functional outcome.Results: Of the 54 patients, 28 (58.85%) were in the age group of 30-40 years. The most common fracture pattern identified was A3 type (48.14%).The mean (± SD) duration of surgery for anteromedial humeral plating was 53 ± 5.00 minutes. The time taken for the fracture to unite was less than 16 weeks in the majority or 50 patients (92.59%). Four (7.40%) patients had delayed union. There was no incidence of iatrogenic radial nerve palsy. Rodriguez – Merchan criteria showed that 37(68.51%) of the patients had good and 12 (22.22%) had excellent functional outcome.

Molecular phylogeny of Indonesian Zeuzera(Lepidoptera:Cossidae) wood borer moths based on CO I gene sequence

Zeuzera is one of the most important wood borer pests in South East Asia. Like of most other genera of moths, the systematic of this genus is still in dispute, especially on the monophyly and the relationship within this genus due to the fact that genus is very varied. This genus was defined based on external characters only such as cross vein Sc-Rs present, humeral plate approximately triangular in shape and anal plate moderately long to moderately short. Therefore, the monophyly of this genus need to be evaluated based on more comprehensive data. To clarify the monophyly of the genus Zeuzera, to reveal the phylogenetic relationships among the Indonesian species, and to establish the genetic characters of Indonesian Zeuzera, we analyzed seven species of Indonesian Zeuzera including three other species distributed around the world based on nucleotide sequence variation across a 580-bp region in the CO I gene. The results showed that the monophyly of Zeuzera was supported by bootstrap tests at the MP and ML tree building methods (>95%). Genus Zeuzera was divided into two groups (A and B) with Z. borneana was excluded from the two groups and occupied at the basal node. Indonesian species was distributed into two different clades. CO I gene alone was able to fully resolve the relationships among species within clade B. However, further investigations were needed by including more species and other genes that the more conserved to test the validity of the phylogenetic hypothesis proposed here.

The tricipital aponeurosis--a reliable soft tissue landmark for humeral plating.

This study aims to identify the relationship of the radial nerve as it descends across the humerus with reference to a reliable soft tissue landmark, the tricipital aponeurosis. Following cadaveric dissection of 10 adult humerii, the radial nerve was located as it crossed the lateral midsagittal point of the humeral diaphysis. A horizontal line was then subtended medially from this point to another line subtended vertically from the lateral border of the tricipital aponeurosis. The vertical distance from this intersection to the lateral apex of the aponeurosis was recorded in three positions (full flexion, 90° of flexion and full extension). The location of the radial nerve on the posterior aspect of the humeral diaphysis to the medial apex of the tricipital aponeurosis was also noted. In 90° of flexion the radial nerve at the lateral midsagittal point of the humerus was 0.9 mm proximal to the lateral apex of the tricipital aponeurosis. Flexion and extension of the elbow changed the interval to 16.3 mm (nerve proximal) in full flexion and 7.1 mm in full extension (nerve distal). On the posterior aspect of the humerus the radial nerve was 21.8 mm proximal to the medial aspect of the tricipital aponeurosis. The aponeurosis provides a reference point from which the nerve can be easily located on the lateral aspect of the humerus intraoperatively in a range of positions, whilst the medial apex provides a guide to the location of the nerve on the posterior aspect of the arm.

Clinical efficacies of different internal fixation materials in the treatment of senile proximal humerus fractures

To explore the clinical efficacies of different internal fixation materials in the treatment of senile proximal humerus fractures. A total of 284 hospitalized patients of proximal humerus fractures over 60 years of age cases from October 2009 to February 2012 were randomly divided into two groups of locking proximal humeral plate (LPHP) and PHILOS (n = 142 each). And the clinical efficacies of two groups were compared. For PHILOS and LPHP groups, the fracture healing periods were (11.64 ± 3.81) and (14.95 ± 3.95) weeks. And there was statistical significance (P < 0.05). At 3 months post-surgery, the incidence of pain was 72.41% and 64.81%. And there was statistical significance (P < 0.05). At 2 years,Neer shoulder function score had inter-group statistically insignificant difference (P > 0.05). Both PHILOS and LPHP are effective in the treatment of senile proximal humeral fractures.However, the former is conducive to fracture healing and has shorter healing time and lowered postoperative pain.

A Technical Note to Improve Surgical Access, When Fixing Proximal Humeral Fractures With the AxSOS Lateral Proximal Humeral Plate (Stryker)

Fixation of proximal humeral fractures with a low profile contoured locking proximal humeral plate is a well recognized and practiced technique. Open reduction and internal fixation of these fractures is typically performed through either a delto-pectoral or deltoid splitting approach. In our unit the AxSOS (Stryker) lateral proximal humeral plate is utilized for the fixation of proximal humeral fractures through a delto-pectoral approach. This plate is shaped to the proximal humerus so that the distal part of the plate is contoured to sit more posteriorly on the shaft of the humerus compared with the proximal part. By utilizing the contralateral lateral proximal humeral plate, that is, the right-sided plate on a left humerus, the access to the distal end of the plate is greatly improved and avoids difficult access or the need to detach part of deltoids’ insertion. In the senior author’s experience, due to the contour of the plate, the distal end of the correctly sided (ipsilateral) plate has a tendency to lie posteriorly to the insertion of deltoid. The resultant plate position is therefore often technically challenging to achieve drill guide and locking screw insertion. By using the contralateral-sided plate it allows for an improved distal plate position that is readily accessible and avoids the requirement for excessive retraction or detachment of deltoids insertion.

The mechanical benefit of medial support screws in locking plating of proximal humerus fractures.

BackgroundThe purpose of this study was to evaluate the biomechanical advantages of medial support screws (MSSs) in the locking proximal humeral plate for treating proximal humerus fractures.MethodsThirty synthetic left humeri were randomly divided into 3 subgroups to establish two-part surgical neck fracture models of proximal humerus. All fractures were fixed with a locking proximal humerus plate. Group A was fixed with medial cortical support and no MSSs; Group B was fixed with 3 MSSs but without medial cortical support; Group C was fixed with neither medial cortical support nor MSSs. Axial compression, torsional stiffness, shear stiffness, and failure tests were performed.ResultsConstructs with medial support from cortical bone showed statistically higher axial and shear stiffness than other subgroups examined (P<0.0001). When the proximal humerus was not supported by medial cortical bone, locking plating with medial support screws exhibited higher axial and torsional stiffness than locking plating without medial support screws (P≤0.0207). Specimens with medial cortical bone failed primarily by fracture of the humeral shaft or humeral head. Specimens without medial cortical bone support failed primarily by significant plate bending at the fracture site followed by humeral head collapse or humeral head fracture.ConclusionsAnatomic reduction with medial cortical support was the stiffest construct after a simulated two-part fracture. Significant biomechanical benefits of MSSs in locking plating of proximal humerus fractures were identified. The reconstruction of the medial column support for proximal humerus fractures helps to enhance mechanical stability of the humeral head and prevent implant failure.

Biomechanical effects of calcar screws and bone block augmentation on medial support in locked plating of proximal humeral fractures

BackgroundThe objective of this study was to investigate the biomechanical effects of medial fracture gap augmentation in locked plating of an unstable 2-part proximal humeral fracture with calcar screws and insertion of a corticocancellous bone block. Furthermore the mechanical behavior of dynamic locking screws in the non-parallel arrangement of a proximal humeral plate was of interest. MethodsThirty-two fresh frozen humeri were randomized in four equal groups. An unstable 2-part fracture was fixed by locked plating in all specimens. The basic screw setup was supplemented by additional calcar screws in one group. Humeral head screws were replaced by dynamic locking screws in a second group. The third group featured an additional corticocancellous femoral head allograft. Assessment of stiffness was followed by cyclic loading and load to failure tests. Resulting stiffness, fracture gap deflection and ultimate load were compared utilizing Bonferroni corrected t-test for independent samples. FindingsThe mechanical effect of additional calcar screws was non-significant as compared to the basic screw configuration whereas bone block insertion significantly increased construct stiffness and failure load. The use of dynamic locking screws did not significantly reduce construct stiffness when compared to conventional locking screws. InterpretationAdditional calcar screws alone did not improve the initial biomechanical properties of an unstable 2-part proximal humeral fracture model. However bone block augmentation appeared to be a reliable alternative of additional bony support by raising stiffness and failure load. Dynamic locking screws did not show their expected dynamic component when used in a non-parallel arrangement.

Arthroscopy After Locked Plating of Proximal Humeral Fractures: Implant Removal, Capsular Release, and Intra-articular Findings

The purpose of this study was to determine the outcomes of arthroscopy after proximal humeral plating and the occurrence of concomitant pathology and avascular necrosis. Forty-five patients (28 women; median age, 58.5 years [range, 30 to 82 years]) underwent arthroscopies of 46 shoulders because of unsatisfactory results after locked plating of proximal humeral fractures. They were prospectively followed up for 3, 12, and 24 months postoperatively. Relevant intra-articular lesions were documented. The patients were assigned to 1 of the following groups: (1) articular screw perforation, (2) subacromial plate impingement, or (3) post-traumatic/postoperative shoulder stiffness. Shoulder range of motion and function as measured with the age- and gender-adjusted Constant-Murley score, as well as the Simple Shoulder Test, were compared among the groups. Concomitant lesions of the articular cartilage, long head of the biceps tendon, tuberosities, and rotator cuff were found in 34 patients (75%). Two-thirds of patients (n = 31) had a partial or complete 270° capsular release. Of the patients, 84% (n = 38) underwent 3 and 12 months' follow-up and 82% (n = 37) underwent 24 months' follow-up. The active range of abduction (P = .029), flexion (P = .048), and internal rotation (P = .0005) had improved significantly at 24 months' follow-up compared with the preoperative status. The mean adjusted Constant-Murley score of patients with post-traumatic shoulder stiffness (n = 15, 64.2% ± 7.9%) and articular screw perforation (n = 19, 73.3% ± 8.4%) was significantly lower (P = .0089 and P = .042, respectively) than that of patients with subacromial plate impingement (n = 12, 93.4% ± 4.3%). High rates of relevant articular pathologies and the necessity of capsular release in a majority of patients with unsatisfactory results after locked plating of proximal humeral fractures make arthroscopy a valuable revision tool with promising results in cases of high plate positioning, screw perforation, and postoperative/post-traumatic shoulder stiffness. Level IV, therapeutic case series.

Efficacy of pressurized proximal humerus proximal humeral locking plate fractures

Objective To observe the clinical efficacy of relatively proximal humeral locking compression plate（ LPHP） with the traditional plate for treatment of proximal humeral fractures .Methods The proximal humeral fractures in patients with 58 cases,the patients were divided into two groups ,the treatment group of 32 cases of locking compression plate in the treatment of T plate ,clover plate in the treatment of 26 patients of the control group received traditional.According to the Neer score compared with two groups of patients with postoperative recovery and compli -cations.Results All the 58 patients for 11 ~15 months of follow-up,the treatment group found no fracture ,fracture nonunion,screw and plate humeral head necrosis ,4 cases of shoulder pain was limited;15 cases of excellent score Neer function,good in 12 cases,5 cases,the excellent and good rate was 84.4%.The control group had 3 cases,2 ca-ses of screw loosening of plate fracture ,3 cases of nonunion ,2 cases of humeral head necrosis ,7 cases of shoulder pain limited.6 cases of excellent score Neer function ,good in 9 cases,3 cases,poor in 8 cases,the excellent and good rate was 57.7%.There was significant differences between the two groups （χ2 =5.113,P <0.05） excellent rate. Conclusion LPHP exact treatment of proximal humeral fractures has fewer complications , which can help patients with early rehabilitation exercises . Key words: Bone wires; Fracture fixation,internal; Humerus fractures

Outcome of locking compression plating for proximal humeral fractures: a prospective study.

To evaluate the outcome of open reduction and internal fixation using locking compression plates for proximal humeral fractures. 54 men and 16 women aged 28 to 79 (mean, 54) years underwent open reduction and internal fixation using a locking compression plate for closed 2-part (n=22), 3-part (n=38), and 4-part (n=10) proximal humeral fractures. 10 of the patients also had dislocation of the humeral head; 4 had fractures extending to the shaft. Wound condition, functional outcome, bone union, amount of collapse, and malalignment were assessed. Functional outcome was assessed using the Constant-Murley score. RESULTS; The mean follow-up period was 15 (range, 6-24) months. All fractures achieved union after a mean of 9 (range, 6-12) weeks. The mean Constant-Murley scores for the injured and normal shoulders were 72 and 82, respectively (88% of normal). The final outcome was excellent in 14 patients, good in 28, moderate in 22, and poor in 6. In the latter 6 patients, 2 had screw penetration, 2 had plate impingement, one had a mal-reduced greater tuberosity, and one had adhesive capsulitis. All were preventable. In all, 18 patients had 20 complications: subacromial impingement of the plate (n=6), mal-reduction of the greater tuberosity (n=6), screw penetration (n=2), adhesive capsulitis (n=2), superficial infection (n=2), and haematoma (n=2); 12 of these complications were technique-related. Locking proximal humeral plates enabled stable fixation in all Neer-type proximal humeral fractures. Most complications were technique-related.

Mismatch of AO anatomically shaped distal humeral plate with humeral shaft forward flexion angulation in adult Chinese population

LCP extra-articular distal humerus plate (LCPEA) designed by AO has been introduced as an anatomically shaped plate that improves the results of surgical fixation in extra-articular distal humeral shaft fractures. However, no study analyzed whether LCPEA matches humeral shaft forward flexion angulation (FFA). The aims of this study were to evaluate the morphological discrepancies between LCPEA and the humeral shaft FFA in Chinese cadaveric dried adult humeri and to propose a further design of pre-contoured plates to accommodate the FFA. Forty-four Chinese cadaveric dried adult humeri were used for this study. An eight-hole LCPEA was applied to the posterior aspect of the distal humerus according to the contour. Mismatches between the bone and the plate were recorded. The distance between the inner surface of the plate and the underlying humeral dorsal cortex was measured at the sites of mismatch. The humeral shaft FFA was measured from the intersection angle between tangent lines placed on the dorsal aspect of the 1/3 distal humeral shaft and the dorsal ridge of the 2/3 proximal humeral shaft. The location of the apex of the FFA was determined by measuring the distance from the most distal point of trochlea of humerus to the point of intersection of the FFA tangent lines. The distance was defined as forward flexion distance (FFD). Mismatch was found at the level of proximal 3-6 holes of LCPEA with an average distance of 6.9 ± 3.1 mm (range 2.3-14.0 mm) at the tip of the plate. The FFA was present in all specimens. The average FFA was 8.2° ± 2.2° (range 4°-13°), the average FFD was 99.9 ± 9.6 mm (range 79.2-117.9 mm), and the average ratio of FFD to humerus length was 0.33 ± 0.03 (range 0.27-0.39). A rather consistent pattern of mismatch was found at the proximal part of LCPEA. An attempt to fit the plate to the bone at this level may cause a gap of the fracture at the opposite cortex. The main reason for the mismatch is the existence of the humeral shaft FFA. LCPEA is usually made a bend of about 8° between the fourth and the fifth dynamic-compression portion of the combination hole in the distal-to-proximal direction.

The interference of distal humeral plating with the medial and lateral collateral ligaments of the elbow

The aim of the present study was to determine the anatomical relationship and evaluate the potential interference of today's common distal humerus plates with the medial and lateral collateral ligaments of the elbow. The elbow joints of 23 embalmed upper extremities were dissected. Three different brands of distal humerus double-plating systems were applied in a standardized fashion. We used a caliper to measure the amount of absolute overlap of the plates on the corresponding collateral ligaments. The data show contact and overlap with the medial and lateral collateral ligaments in all tested medial and lateral plates. The posterolateral and posteromedial plates showed no contact with the ligaments, yet they did contact the posterior joint capsules. The medial plates showed less contact/overlap when compared with the lateral and extended medial plates. Based on the present data, we conclude that distal humerus plating using the perpendicular technique with standard-sized medial plates shows the least amount of overlap over the medial and lateral collateral ligaments. The extent of the overlap of the ligaments by the humeral plates is clearly shown in the present study.

Relationship between axillary nerve and percutaneously inserted proximal humeral locking plate: a cadaver study.

The aim of this study was to investigate the relationship between the axillary nerve and the percutaneously inserted proximal humeral locking plate and to evaluate the risk of axillary nerve injury during percutaneous plate insertion. The study included 50 shoulders of 25 fresh frozen cadavers. A 5 cm incision was made from the anterolateral border of the acromion to the arm and a 5-hole 3.5-mm proximal humeral plate was inserted. The axillary nerve was then dissected. Plate holes which crossed the axillary nerve were noted. The distance between the axillary nerve and the lateral edge of the acromion and the length of the arm were measured and their relations evaluated with a correlation test. The average arm length was 319 mm. The average distance between the axillary nerve and the lateral edge of the acromion was 60 mm. There was a significant correlation between the arm length and acromion-axillary nerve distance (p<0.05). The plate was inserted under the deltoid fascia in all shoulders except one. There were no axillary nerve lesions. In 1 case, the distal end of the plate was inserted in the deltoid muscle. No constant relationship between the plate holes and the axillary nerve was detected. There is a risk of axillary nerve injury during percutaneous plate insertion. It must be ensured that the plate is inserted under the deltoid fascia during the surgery. The axillary nerve must be visible during application of the screws due to the impossibility of knowing which holes cross the axillary nerve.