Intraoperative visualization of the posterolateral ulnohumeral joint space is reliable to indicate overlengthening in radial head arthroplasty.

INTRODUCTION: Avoiding overlengthening in radial head arthroplasty (RHA) is essential for the prognosis of the elbow joint. An overlengthening from 2 mm is visible due to widening of the anterolateral ulnohumeral joint space but intraoperatively, this particular joint space is difficult to visualize. The commonly used Kocher approach allows visualization of the posterolateral joint space without additional instruments or further surgical release of the already unstable elbow. The aim of our study was to investigate whether the visualization of the posterolateral joint space is also a reliable method to indicate overlengthening in RHA. MATERIAL AND METHODS: RHA was performed in five human cadaveric specimens with the forearm, wrist, and hand intact. The lateral ligament complex was detached and an anatomic transosseous refixation was performed. Six stages of implantation heights were documented: native joint (1), RHA at the anatomic height (2), + 2 mm (3), + 4 mm (4), + 6 mm (5) and - 2 mm (6). Macroscopic measurement and digital image analysis of the posterolateral and anterolateral ulnohumeral joint spaces were performed. RESULTS: All stages of overlengthening showed a significant increase in posterolateral and anterolateral joint space widening (p < 0.05). The posterior and anterior joint space showed excellent intraclass correlation. CONCLUSION: Visualization of the posterolateral aspect of the ulnohumeral joint space is a reliable indicator for overlengthening in RHA without further compromising an already unstable elbow. Correlation to the findings of the anterolateral ulnohumeral joint space in different implants leads to the assumption that visualization of either the anterior or posterior ulnohumeral joint space is universally applicable to determine overlengthening in RHA, regardless of the type of the radial head implant.

Advanced Surgical Trauma Care Course - Evaluation of a Fracture Simulation Course Concept with Intact Soft Tissue.

PURPOSE: Currently, surgical training in the clinical scenario is limited by duty-hour restrictions as well as an increasing specialization within the numerous surgical fields. In such an environment, surgical training in subspecialties becomes both, more important and challenging. Against this background, purpose of the present study was to evaluate a new course format for advanced training in fracture treatment. In the studied course format, cadaveric wrist or elbow specimens with prefabricated fractures were used with the aim of improving the learning effect for the attendees. On these specimens, operative treatment with specific osteosynthetic implants was performed under radiographic control. We hypothesized that simulation in a complex scenario such as the one used in the studied course format leads to a subjectively better learning effect regardless of prior surgical experience. METHODS: 205 participants in 16 courses between 2016 and 2018 were surveyed regarding their operative experience, previously attendances of trauma care trainings and subjective learning effect in the surveyed course and the trainings attended previously. Based on a ten-step scale, results in the subjective learning effect were compared between the investigated course and other trainings and to the individual operative experience. RESULTS: The learning effect of the surveyed fracture courses was assessed with a median of 9/10 for the theoretical part and 10/10 for the practical part, significantly better than in trainings attended previously. The surveyed participants reported that they each performed 308 operations per year on average. Other course formats were attended significantly more frequent than courses on prefractured human specimens. The respondents reported a subjectively higher learning effect of the evaluated course concept in comparison to previously attended courses in practical and theoretical aspects. CONCLUSIONS: The reported innovative course format is an efficient concept for education in surgical trauma care, suited for more novice and advanced surgeons.

Plate Osteosynthesis of Proximal Ulna Fractures-A Biomechanical Micromotion Analysis.

PURPOSE: Double plating has been promoted, in recent years, as an alternative treatment method for proximal ulna fractures. This study aimed to compare the biomechanical properties of double-plate osteosynthesis with posterior plate fixation using a novel investigational design utilizing a 3-dimensional camera system to analyze fracture micromotion. METHODS: Fourteen fresh-frozen specimens were available for this study. Mayo type IIA fractures of the olecranon were created and internal fixation was performed with either an angular stable posterior plate or angular stable double plates. Fracture micromotion was evaluated by means of digital image correlation with a 3-dimensional camera system before and after dynamic cyclic loading from 15° to 90° of elbow flexion with a pulling force of 25 N to 80 N. RESULTS: Micromotion of fragments was less pronounced in double-plate osteosynthesis when compared with single plates before and after cyclic loading. However, overall results were similar. Two of the single plates failed during cyclic loading but there were no failures in the double plates. CONCLUSIONS: This biomechanical analysis shows that single and double plating results in comparable stability of fixation. Although the double-plating technique tends to provide more stable fixation, relevant differences were not observed. CLINICAL RELEVANCE: Double plating potentially represents an efficient option for fixation of proximal ulna fractures. It could decrease the risk of soft tissue complications owing to their low profile and the superior soft tissue coverage.

The circumferential graft technique for treatment of multidirectional elbow instability: a comparative biomechanical evaluation.

BACKGROUND: Ligament reconstruction with a circumferential graft represents an innovative technique for treatment of multidirectional elbow instability. This biomechanical study compared the stability of the intact elbow joint with the circumferential graft technique and the conventional technique. METHODS: Seven fresh frozen cadaveric elbows were evaluated for stability against valgus and varus/posterolateral rotatory forces (3 Nm) over the full range of motion. Primary stability was determined for intact specimens, after sectioning of the collateral ligaments, after applying the circumferential graft technique (box-loop), and after conventional collateral ligament reconstruction. Cyclic loading (1000 cycles) was performed to assess joint stability and stiffness of the native ligaments and the tendon grafts. RESULTS: Primary stability of both reconstruction techniques was equal to the native specimens (P = .17-.91). Sectioning of the collateral ligaments significantly increased joint instability (P < .001). The reconstruction techniques provided equal stability after 1000 cycles (P = .78). Both were inferior to the intact specimens (P = .02). Cyclic loading caused a significantly lower increase in stiffness of the native ligaments compared with the tendon grafts of either reconstruction technique (P = .001-.008). Significantly better graft stiffness was retained with the circumferential graft technique compared with conventional reconstruction (P = .04). CONCLUSION: Neither reconstruction technique fully reproduces the biomechanical profile of the native collateral ligaments. The circumferential graft technique seems to resist cyclic loading slightly better than the conventional reconstruction technique, yet both reconstruction techniques provide comparable stability.

Fractures of the Radial Head.

Radial head fractures are the most common fractures around the elbow. Because they are often accompanied by ligamentous injuries, we recommend considering them to be osteoligamentous injuries rather than simple fractures, even in undisplaced or minimally displaced fractures. Surgeons should always suspect and actively exclude concomitant ligament tears. The incidence of these associated injuries increases with greater severity of the radial head fracture. However, the standard Mason classification system does not adequately address this problem, and all attempts to establish a new classification system that provides concise treatment algorithms have failed. This article discusses the current treatment options and the current controversies in nonsurgical therapy, open reduction and internal fixation (ORIF) and radial head replacement.

Peri-implant failure in dual plating of the distal humerus-A biomechanical analysis with regard to screw and plate positioning.

PURPOSE: The aim of this biomechanical study was to analyse the influence of plate and screw positioning on peri-implant failure in dual plate osteosynthesis. We hypothesized that screw positioning rather than plate configuration influences the risk of peri-implant fractures. METHODS: Twenty macerated humerus specimens were available. 5 groups of 4 were built according to specimen size. Locking dual plates (Medartis, Switzerland) were randomly applied to the distal humerus of the specimens in 4 types of configuration: Bending forces were applied using a universal testing machine until peri-implant fracture occurred. RESULTS: Mean failure loads for respective configuration types were as follows: P1: 428.7 (±84.2) N, A1: 410.0 (±54.7) N, A0: 297.8 (±48.3) N, P0: 261.0 (±65.0) N. Configurations with positioning of the most proximal screws at different levels (P1, A1) reached significantly higher failure loads when compared to screw placement at the same level (P0, A0) (0.01≤p≤0.03). Altering the plate configuration did not significantly influence failure loads (0.34≤p≤0.58). CONCLUSIONS: The results of this study suggest that placement of the most proximal screws rather than the configuration of the plates is critical regarding the predetermined risk of peri-implant failure in dual plate osteosynthesis of the distal humerus. Varying levels of the outermost screws of corresponding double plates seem to be crucial to avoid complications related to the osteosynthesis.

From radial head to radiocapitellar to total elbow replacement: A case report.

INTRODUCTION: Radiocapitellar arthroplasty represents a possible treatment option for isolated osteoarthritis of the radial column. We report the first case of early failure of this procedure. PRESENTATION OF CASE: We present the case of a 41-year old male who sustained a terrible triad injury to his right elbow and subsequently underwent radial head arthroplasty. Due to overstuffing of the radial head prosthesis, capitellar erosion occurred and radiocapitellar arthroplasty was thus performed. Only one year later, conversion of the radiocapitellar replacement to total elbow arthroplasty was required as a result of progressive ulnohumeral osteoarthritis. DISCUSSION: According to the currently limited clinical data, radiocapitellar arthroplasty provides satisfactory results. However, biomechanical analysis shows that available prostheses do not sufficiently reproduce the radiocapitellar anatomy. The design of the prosthesis might thus have contributed to the rapid progression of ulnohumeral erosion following radiocapitellar arthroplasty although the poor outcome may also be attributed to the trauma itself along with the inadequate initial treatment. CONCLUSIONS: The indication for radiocapitellar arthroplasty warrants careful consideration given the results of biomechanical analysis and the early failure due to progressive ulnohumeral erosion seen in the present case.

Reliability of Magnetic Resonance Imaging Signs of Posterolateral Rotatory Instability of the Elbow.

PURPOSE: To evaluate radiographic signs of posterolateral rotatory instability (PLRI) on magnetic resonance imaging (MRI). The goal was to establish objective radiographic criteria to aid in the diagnosis of PLRI. METHODS: The MRI scans of 60 patients were evaluated retrospectively. Two study groups were compared. Group 1 (n = 30) consisted of unstable elbows in which PLRI was confirmed by clinical examination and arthroscopy. Group 2 (stable; n = 30) served as the control group. Patients in group 2 had transient epicondylitis without clinical suspicion of instability. Joint incongruity was analyzed for sagittal views through the radial head and the coronoid tip and for coronal and axial views. Interobserver and intra-observer reliability were evaluated. RESULTS: In the sagittal view through the radial head, average radiocapitellar incongruity differed significantly between groups 1 and 2. In addition, mean ulnohumeral incongruity in an axial view through the motion axis of the distal humerus showed significant differences between groups. Sagittal views through the tip of the coronoid and coronal views did not reveal significant differences in patients with unstable elbows compared with the control group. CONCLUSIONS: The current study provides useful MRI criteria indicative of PLRI when combined with physical examination. Cutoff points of 1.2 mm for radiocapitellar incongruity (sagittal view) and 0.7 mm for axial ulnohumeral incongruity (axial view) are suitable to screen for PLRI. Radiocapitellar incongruity greater than 2 mm and axial ulnohumeral incongruity greater than 1 mm are highly suspicious of elbow instability. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.

The treatment of simple elbow dislocation in adults.

BACKGROUND: Simple elbow dislocation is a complex soft-tissue injury that can cause permanent symptoms. Its incidence is 5 to 6 cases per 100 000 persons per year. Its proper treatment is debated; options range from immobilization in a cast to surgical intervention. METHODS: We systematically reviewed the literature on the treatment of simple elbow dislocation and performed a meta-analysis, primarily on the basis of clinical scores and secondarily with respect to pain, range of motion, and return to work. RESULTS: A randomized controlled trial (RCT) showed that clinical results at short-term follow-up were superior for early functional treatment compared to immobilization in a cast. Brief immobilization, however, reduced pain initially, and the long-term results of early mobilization and immobilization in a cast were the same. Our meta-analysis showed that early mobilization enables patients to return to work earlier (difference of mean values -2.91, 95% confidence interval [CI] -3.18 to -2.64), and that the extent of soft-tissue injury is correlated with the clinical outcome (inverse relationship; difference of mean values -12.07, 95% CI -23.88 to -0.26). Surgical and conservative treatment were compared in a single RCT, which revealed no significant difference in outcomes. A meta-analysis of two retrospective comparative studies showed no advantage of immediate ligament repair over delayed surgery. CONCLUSION: Early functional treatment is the evidence-based therapeutic standard for simple elbow dislocation. The past few years have seen further developments in surgery for simple elbow dislocation. Further study is needed to determine whether surgery for elbow dislocation with high-grade instability can prevent persistent pain, limitation of motion, and chronic instability.

Anatomic relations between the lateral collateral ligament and the radial head: implications for arthroscopic resection of the synovial fold of the elbow.

PURPOSE: The purpose of this study was to determine the anatomic relationship between the radial head and the lateral collateral ligament (LCL) and when the LCL would be at risk of iatrogenic injury during arthroscopic resection of the synovial fold. METHODS: Thirty-four formalin-fixed upper extremities were dissected. A projection of the LCL onto the radial head was marked with a needle. The percentage of the posterior border of the radial head overlaid by the LCL was digitally measured. A portion of the projection of the LCL was statistically correlated with the overall diameter of the radial head. RESULTS: The overall diameter of the radial head was 21.2 mm ± 2.3. The proportionate projection of the medial border of the LCL onto the radial head was 5.3 ± 1.6 mm on average. The lateral 25 % of the radial head was overlaid by the LCL with a maximum value of 40 % on average. The inter- and intraobserver reliability showed very good accordance with the digital measurements (r > 0.8). CONCLUSION: Care must be taken when performing a resection in the lateral 40 % of the radial head, whereas resection in the medial 60 % of the radial head appears to be safe. The LCL is an important stabiliser of the elbow joint, a lesion of which by undeliberate arthroscopic dissection may lead to joint instability. Iatrogenic injury to the LCL presumably can be prevented when respecting the given data. LEVEL OF EVIDENCE: Experimental study.

Impact of posterior tibial nail malpositioning on iatrogenic injuries by distal medio-lateral interlocking screws. A cadaveric study on plastinated specimens.

In intramedullary tibial nailing, multi-planar locking makes stabilization of proximal and distal metaphyseal fractures possible. A known complication in intramedullary nailing of the tibia is iatrogenic injury to neuro-vascular structures caused by the insertion of locking screws. As shown in previous studies, the distal positioning of the nail is important, as it determines the course of the locking bolts. The goal of the present study was to display the consequences of posterior nail malpositioning with respect to the safety of the distal medio-lateral locking screws and the available options. Human cadaveric legs were plastinated according to the sequential plastination technique after intramedullary nailing of the tibia and were then cut transversely. The tibial nails were placed centrally or posteriorly. Macroscopic analysis showed a distinct drawback of posterior nail positioning, with diminished options for the placement of the locking screws and thereby a risk of damaging the anterior and posterior neuro-vascular bundles by distal medio-lateral locking screws.

Anatomic fit of six different radial head plates: comparison of precontoured low-profile radial head plates.

PURPOSE: Bulky implants may lead to symptomatic soft tissue irritation after open reduction and internal fixation of radial head and neck fractures. The purpose of our study was to compare the anatomic fit of precontoured radial head plates. METHODS: We stripped 22 embalmed human cadaveric radiuses of soft tissues. We investigated 6 radial head plates: (1) the Medartis radial head buttress plate (MBP), (2) the Medartis radial head rim plate (MRP), (3) the Synthes radial neck plate (SNP), (4) the Synthes radial head plate (SHP), (5) the Acumed radial head plate (AHP), and (6) the Wright radial head plate (WHP). Each plate was applied to each radial head at the place of best fit within the safe zone. We tested 4 parameters of anatomic fit: (1) plate-to-bone distance, (2) plate contact judged by 3 different observers, (3) pin-subchondral zone distance, and (4) plate-to-bone contact after adjustment of the plates. RESULTS: The MBP and MRP showed the lowest profile by objective measurements, the SNP and AHP had a moderate profile, and the SHP and WHP demonstrated the bulkiest profile. The subjective assessments also demonstrated the best fit for the MBP, a good fit for the SNP, a moderate fit for the MRP and AHP, and a poor fit for the SHP and WHP. The MBP, MRP, and AHP could always provide pin-subchondral zone contact, unlike the SHP, SNP, and WHP. After bending, significant improvement of plate-to-bone distance could only be seen for the MBP, MRP, and WHP. The ranking among plates remained the same except for the WHP, which showed a significantly lower plate-to-bone distance than the SHP. CONCLUSIONS: Currently available radial head implants are heterogeneous. The MBP and MRP showed the lowest profile and best anatomic fit. Owing to the complex radial head anatomy, to date there is no one radial head plate that perfectly fits all radial heads. CLINICAL RELEVANCE: Conformance of existing plates to the radial head and neck is not perfect. Careful plate selection and modification, when necessary, may minimize interference of this hardware with the surrounding soft tissues and facilitate recovery of motion.

Mid- to long-term results after bipolar radial head arthroplasty.

BACKGROUND: Radial head arthroplasty is considered the treatment of choice for unreconstructable radial head fractures in the acute fracture situation. Although short-term results in the current literature are promising, replacement of the radial head remains controversial as long-term results are still missing. We report our 8.8-year results after treatment with a bipolar radial head prosthesis by Judet. MATERIALS AND METHODS: In our department, 19 patients were treated with bipolar radial head arthroplasty between 1997 and 2001. Seventeen of these patients-14 men and 3 women-were examined retrospectively after 106 months (range, 78-139). Of these, 9 patients were treated primarily, 7 patients secondarily, and 1 because of a tumor. RESULTS: On the Mayo Elbow Performance Score, 6 patients achieved excellent results, 10 good, and one fair. The mean DASH score was 9.8 (range, 0-34). No differences were seen between primary and secondary implantation. Flexion averaged 124° (range, 110-150°), the extension deficit was 21° (range, 0-40°), pronation 64° (range, 30-90°), and supination 64° (range, 30-90°). The following complications were seen: 2 dislocations and 8 cases of degenerative changes of the capitellum, 1 with severe erosion. Signs of ulnohumeral arthrosis were found in 12 patients. No evidence of loosening, radiolucencies, or proximal bone resorption was detected. CONCLUSION: Despite major primary complications and high incidence of radiographic signs of degenerative changes after 8.8 years, mainly good clinical results were achieved with Judet's bipolar prosthesis.

[Treatment of the complex intraarticular fracture of the distal humerus with the latitude elbow prosthesis]. / Behandlung der komplexen intraartikulären Fraktur des distalen Humerus mittels Latitude-Ellenbogenprothese.

OBJECTIVE: Therapy of comminuted intraarticular distal humerus fractures in elderly patients with primary total elbow arthroplasty to achieve stable and painless function. Use of "third-generation" elbow prosthesis with the following options:--linked total elbow arthroplasty,--unlinked total elbow arthroplasty,--either with or without radial head replacement,--hemiarthroplasty. INDICATIONS: Comminuted intraarticular distal humerus fractures with poor bone quality, in which stable osteosynthesis is impossible. Failure of internal fixation without the technical possibility of revision osteosynthesis. Posttraumatic osteoarthritis or rheumatoid arthritis. CONTRAINDICATIONS: Open fractures (Gustilo-Anderson type II or III) or contaminated wounds should not initially be treated with total elbow arthroplasty. Prosthetic replacement may be considered after consolidation of the soft tissue. Low compliance, high functional demands. Paralysis of the biceps muscle. SURGICAL TECHNIQUE: Supine positioning of the patient. Surgical approach after Bryan-Morrey. Anterior transposition of the ulnar nerve. Preparation of the insertion of the triceps at the distal humerus, capsule and proximal ulna. Reflection of the triceps in continuity with the ulnar periosteum and the forearm fascia. Attempt at reconstruction of the epicondyles to achieve ligamentary stability and to implant an unlinked prosthesis. If this is technically not possible, the prosthesis is linked at the end of the operation. Removal of the distal humerus fragments. Determination of the prosthesis size. Detection of the extension-flexion axis. Opening of the humeral intramedullary canal. Determination of the offset. Preparation of the humeral prosthesis repository. Placement of the trial prosthesis. Potential implantation of a hemiprosthesis, if radial head, proximal ulna and ligaments are unaffected. Otherwise preparation of the ulnar prosthesis repository. If the radial head is unaffected, it can be preserved. Otherwise it has to be resected and preferably replaced. Placement of the ulnar and radial trial prosthesis. After correct trial reposition cementing of all definitive prosthesis components with attachment of a cortical bone graft behind the ventral flange of the humeral component. If there is no sufficient stability at the end of the operation, the prosthesis must be linked by insertion of the ulnar cap. POSTOPERATIVE MANAGEMENT: Postoperative anterior upper-arm splint in full extension. Active motion. No active extension for 6 weeks. Avoidance of single-event weight lifting>5 kg, no repetitive weight lifting>1 kg, and no forced elbow movements, e.g., racquet sports. RESULTS: 15 Latitude elbow prostheses were implanted in 2007 and 2008 at the Department of Trauma Surgery of the University Hospital Mainz, Germany, due to the following indications: fractures (n=7), pseudarthrosis (n=4), posttraumatic osteoarthritis (n=3), and rheumatoid arthritis (n=1). Six hemiprostheses, two unlinked and seven linked prostheses were implanted. The mean age of patients was 67 years (31-88 years). For the treatment of acute fractures, the indication was made only in elderly patients. The mean age was 77 years (66-88 years). Eleven of these 15 patients were reexamined after 13.5 months (6-23 months). The mean extension deficit was 15 degrees (0-30 degrees), the mean flexion 119 degrees (95-140 degrees). The mean pronation was 78 degrees (60-90 degrees), the mean supination 79 degrees (50-90 degrees). According to the Mayo Elbow Performance Score, three patients achieved an excellent, seven a good, and one a fair result. The mean Mayo Score was 89.2 (74-100). The mean DASH (Disabilities of the Arm, Shoulder and Hand) Score was 8.4 (0-28).

Stability of radial head and neck fractures: a biomechanical study of six fixation constructs with consideration of three locking plates.

PURPOSE: Open reduction and internal fixation of radial neck fractures can lead to secondary loss of reduction and nonunion due to insufficient stability. Nevertheless, there are only a few biomechanical studies about the stability achieved by different osteosynthesis constructs. METHODS: Forty-eight formalin-fixed, human proximal radii were divided into 6 groups according to their bone density (measured by dual-energy x-ray absorptiometry). A 2.7-mm gap osteotomy was performed to simulate an unstable radial neck fracture, which was fixed with 3 nonlocking implants: a 2.4-mm T plate, a 2.4-mm blade plate, and 2.0-mm crossed screws, and 3 locking plates: a 2.0-mm LCP T plate, a 2.0-mm 6x2 grid plate, and a 2.0-mm radial head plate. Implants were tested under axial (N/mm) and torsional (Ncm/ degrees ) loads with a servohydraulic materials testing machine. RESULTS: The radial head plate was significantly stiffer than all other implants under axial as well as under torsional loads, with values of 36 N/mm and 13 Ncm/ degrees . The second-stiffest implant was the blade plate, with values of 20 N/mm and 6 Ncm/ degrees . The weakest implants were the 2.0-mm LCP, with values of 6 N/mm and 2 Ncm/ degrees , and the 2.0-mm crossed screws, with values of 18 N/mm and 2 Ncm/ degrees . The 2.4-mm T plate, with values of 14 N/mm and 4 Ncm/ degrees , and the 2.0-mm grid plate, with values of 8 N/mm and 4 Ncm/ degrees came to lie in the midfield. CONCLUSIONS: The 2.0-mm angle-stable plates-depending on their design-allow fixation with comparable or even higher stability than the bulky 2.4-mm nonlocking implants and 2.0-mm crossed screws.