Accessibility of osteochondral lesion at the capitellum during elbow arthroscopy: an anatomical study.

INTRODUCTION: Osteochondrosis dissecans (OCD) at the capitellum is a common pathology in young patients. Although arthroscopic interventions are commonly used, there is a lack of information about the accessibility of the defects during elbow arthroscopy by using standard portals. MATERIALS AND METHODS: An elbow arthroscopy using the standard portals was performed in seven fresh frozen specimens. At the capitellum, the most posterior and anterior cartilage surface reachable was marked with K-wires. Using a newly described measuring method, we constructed a circular sector around the rotational center of the capitellum. The intersection of K-wire "A" and "B" with the circular sector was marked, and the angles between the K-wires and the Rogers line, alpha angle for K-Wire "A" and beta angle for K-wire "B", and the corridor not accessible during arthroscopy was digitally measured. RESULTS: On average, we found an alpha angle of 53° and a beta angle of 104°. Leaving a sector of 51° which was not accessible via the standard portals during elbow arthroscopy. CONCLUSION: Non-accessible capitellar lesions during elbow arthroscopy should be considered preoperatively, and the informed consent discussion should always include the possibility of open procedures or the use of flexible instruments.

[Elbow prosthesis after acute fractures : Indications and technique]. / Ellenbogenprothese nach akuten Frakturen : Indikation und Technik.

Good to very good clinical results can be achieved in older patients with the implantation of a total elbow prosthesis in cases of distal humeral fractures by taking the morphological features of the fractures, the bone quality as well as the individual patient requirements and variables into account. The most commonly used design is the cemented semiconstrained linked total elbow endoprosthesis. The unlinked prosthesis design and hemiarthroplasty require intact or adequately reconstructable musculoligamentous structures or condyles and a preserved or replaced radial head. The recommended weight limit after total elbow prosthesis as well as potential intraoperative and postoperative complications must be considered and discussed with the patients. A secondary total elbow arthroplasty is also possible after primary conservative treatment approaches, e.g., in the case of contraindicated surgery in the fracture situation, persistent pain and functional restrictions. This article provides an overview of the technique and the appropriate indications.

Anatomic evaluation of the triceps tendon insertion at the proximal olecranon regarding placement of fracture fixation devices.

PURPOSE: Olecranon fractures, especially with a small proximal fragment, remain a surgical challenge. Soft tissue irritation and affection of the triceps muscle bear a risk of complications. In order to find an area for a soft-tissue sparing placement of implants in the treatment of olecranon fractures, we aimed to define and measure the segments of the proximal olecranon and evaluate them regarding possible plate placement. METHODS: We investigated 82 elbow joints. Ethical approval was obtained from the local ethics committee, After positioning in an arm holder and a posterior approach we described the morphology of the triceps footprint, evaluated and measured the surface area of the triceps and posterior capsule and correlated the results to easily measurable anatomical landmarks. RESULTS: We found a bipartite insertional footprint with a superficial tendinous triceps insertion of 218.2 mm2 (± 41.2, range 124.7-343.2), a capsular insertion of 159.3 mm2 (± 30.2, range 99.0-232.1) and a deep, muscular triceps insertion area of 138.1 mm2 (± 30.2, range 79.9-227.5). Olecranon height was 26.7 mm (± 2.3, range 20.5-32.2), and olecranon width was 25.3 mm (± 2.4, range 20.9-30.4). Average correlation between the size of the deep insertion and ulnar (r = 0.314) and radial length (r = 0.298) was obtained. CONCLUSIONS: We demonstrated the bipartite morphology of the distal triceps footprint and that the deep muscular triceps insertion area by its measured size could be a possible site for the placement of fracture fixations devices. The size correlates with ulnar and radial length.

Metacarpal fractures - A method to simulate life-like fractures in human cadaveric specimens for surgical education.

Metacarpal fractures are a type of fracture which trauma surgeons face frequently. Restoration of hand function is the primary objective. The aim of this study was to investigate whether life-like fractures of human cadaveric metacarpals with intact soft-tissue envelope could be simulated for surgical education. Six fresh-frozen human distal forearm and hand specimens were fractured on a custom-made drop-test bench. This reproducible method is based on a weight falling from a predefined height onto the fixed specimens. All fractures were analyzed by fluoroscopy and CT. In all specimens included in this study, several typical lesions were created, resulting in a total of 19 metacarpal fractures. There were 6 fractures involving the capital region, 5 metaphyseal fractures with partial involvement of the diaphysis and 7 pure diaphyseal fractures. One metacarpal comprised a trifocal lesion consisting of a metaphyseal undisplaced fracture, a diaphyseal wedge fracture and a non-displaced articular base fracture. Human cadaveric metacarpals with intact soft tissue can be successfully fractured by a drop-test bench setup. The resulting fractures resemble realistic fracture patterns. Load and exact load angle seem to be critical. Such fractured specimens can be used in surgical education courses. Courses providing fractured specimens with intact soft-tissue envelope can improve clinical teaching for young surgeons and experts alike.

[Radial head fractures : Epidemiology, diagnosis, treatment and outcome]. / Radiuskopffrakturen : Epidemiologie, Diagnose, Behandlung und Outcome.

Radial head fractures account for the majority of bony injuries to the elbow. The usual clinical signs include hemarthrosis, pain and limitations in movement. The standard diagnostic tool is radiological imaging using X­rays and for more complex fractures, computed tomography (CT). Concomitant ligamentous injuries occur more frequently than expected and must be reliably excluded. The classification is based on the modified Mason classification. Mason type I fractures are usually treated conservatively with immobilization and early functional aftercare. Mason type II fractures can be well-addressed by screw osteosynthesis but higher grade fractures (Mason types III-IV) can necessitate a prosthetic radial head replacement. In this case, prosthesis implantation is to be preferred to a radial head resection. The outcome after treatment of radial head fractures can be described as good to very good if all accompanying injuries are adequately addressed.

Inducing pilon fractures in human cadaveric specimens depending on the injury mechanism: a fracture simulation.

BACKGROUND: Operative management of pilon fractures, especially high-energy compression injuries, is a challenge. Operative education is of vital importance to handle these entities. Not rarely, it is cut by economics and staff shortage. As public awareness toward operative competence rises, surgical cadaver courses that provide pre-fractured specimens can improve realism of teaching scenarios. The aim of this study is to introduce a realistic pilon fracture simulation setup regarding the injury mechanism. MATERIALS AND METHODS: 8 cadaveric specimens (two left, six right) were fixed onto a custom drop-test bench in dorsiflexion (20°) and light supination (10°). The proximal part of the lower leg was potted, and the specimen was exposed to a high energetic impulse via an axial impactor. CT imaging was performed after fracture simulation to detect the exact fracture patterns and to classify the achieved fractures by two independent trauma surgeons. (AO/OTA recommendations and the Rüedi/Allgöwer). RESULTS: All cadaveric specimens could be successfully fractured: 6 (75%) were identified as a 43-C fracture and 2 (25%) as 43-B fracture type. Regardless of the identical mechanism two different kinds of fracture types were reported. In five cases (62.5%), the fibula was also fractured and in three specimens, a talus fracture was described. There was no statistically significant correlation found regarding Hounsfield Units (HU) and age as well as HU and required kinetic energy. CONCLUSION: A high energetic axial impulse on a fixed ankle specimen in light dorsiflexion (20°) and supination (10°) induced by a custom-made drop-test bench can successfully simulate realistic pilon fractures in cadaveric specimens with intact soft tissue envelope. Although six out of eight fractures (75%) were classified as a 43-C fracture and despite putting a lot of effort into the mechanical setup, we could not achieve an absolute level of precision. Therefore, we suggest that the injury mechanism is most likely a combination of axial loading, shear and rotation. LEVEL OF EVIDENCE: III.

Overlengthening of the radial column in radial head replacement: a review of the literature and presentation of a classification system.

BACKGROUND: Radial head arthroplasty is a common procedure in elbow surgery. It has been shown to be of benefit for the patients, but there also are relevant complications that should be prevented if possible. One significant complication is overlengthening of the radial head prosthesis. In overlengthening, the head of the prosthesis overextends the physiological level of the native radial head and leads to overcompression in the radiohumeral joint. Rapid erosion and arthritic changes may then impede the clinical outcome. The incidence of overlengthening is not precisely known, but estimations range to up to 20% of all implanted prostheses. METHODS: The present review discusses the available body of literature on overlengthening and lines out a classification system that may be used to guide treatment algorithms. The classification is based on the personal experiences of the author during their clinical practice. RESULTS: In low-grade overlengthening (type I) conservative treatment can be an option. In Types II-IV usually revision surgery is needed. Depending on the state of the capitulum and joint stability, it is possible re-implant a prosthesis, or rely on implant removal alone. DISCUSSION: The present review aimed at shedding light into overlengthening as a complication radial head replacement and to help identify and treat it.

[External fixator of the elbow]. / Fixateur externe am Ellenbogen.

AIM OF SURGERY: The placement of an external elbow fixator can be statically carried out as temporary stabilization or as a hinged movement fixator. As a hinged movement fixator a functional follow-up treatment is possible due to control of the joint guidance and reduction of the compromising forces on the osteoligamentous structures. INDICATIONS: As a temporary stabilization of the elbow, the external fixator is used as a damage control method. As a movement fixator it is used as an additional protection and movement control after complex osteoligamentous interventions and persisting tendency to dislocation of the joint and also as a standalone procedure. In some cases, the procedure is also used in distraction arthrolysis of stiff elbows and as a salvage procedure in patients with relevant comorbidities as part of fracture treatment. CONTRAINDICATIONS: Inexperience in relation to the procedure as well as a local acute infection at the level of the intended pin locations should specifically be mentioned as contraindications. In addition, compliance and patient understanding of the procedure are essential for the success of treatment. SURGICAL TECHNIQUE: Soft tissue preparation for pin placement should be preferred over percutaneous incisions to enable a safe bone exposure. Knowledge of the course of neurovascular structures (particularly the radial nerve) is essential. When placing a hinge, knowledge of the position and detection of the idealized center of rotation is of fundamental importance. POSTOPERATIVE MANAGEMENT: The type of postoperative management required essentially depends on the underlying injury. When placing a hinged fixator, the aim is to enable movement as early as possible. Nevertheless, blocking of the hinged fixator may be useful for a short period of time. Adequate pin care over the duration of the treatment is essential in order to prevent complications. RESULTS: Good functional results have been reported for the treatment of unstable elbows after primary and secondary placement of a hinged external fixator. Good functional scores and improvement in the range of motion were also recorded in the context of an arthrolysis (additive for open arthrolysis or distraction arthrolysis); however, in contrast a significant number of complications associated with this surgery are likely to emerge. As a definitive salvage procedure, satisfactory results were obtained in a small case series of a selected older patient group with relevant comorbidities.

[Lower leg, ankle and foot]. / Distaler Unterschenkel, Sprunggelenk und Fuß.

CLINICAL/METHODICAL ISSUE: Bipedal locomotion means high mechanical stress on the lower extremities and susceptibility to fractures. On the one hand, these can be the result of a one-time traumatic stress in the context of high speed traumas or falls, but can also result from repetitive microtraumas with subsequent stress fractures. STANDARD RADIOLOGICAL METHODS: For all fracture entities and localizations, X­ray diagnostics is the basic modality. METHODICAL INNOVATIONS: For optimal surgical reconstruction of intra-articular fractures or in complex fracture configurations, computed tomography should be generously used to improve postoperative outcome. PERFORMANCE: The classification of the individual fractures should enable standardised further therapy planning, especially with regard to conventional or surgical treatment. ACHIEVEMENTS: The combination of X­ray, magnetic resonance imaging and computed tomography makes a reliable diagnosis regarding foot fractures possible. PRACTICAL RECOMMENDATIONS: Important for the use of individual classification systems is always, in addition to clinical relevance, the safe and equal understanding of the individual types and degrees by the radiologist and the referring colleague.

[Surgical approaches to the hand]. / Operative Zugangswege an der Hand.

OBJECTIVE: Accessibility of any anatomical structure of the hand via surgical approach. INDICATIONS: Any surgical treatment of the hand. CONTRAINDICATIONS: Any contraindication to surgical treatment of the hand. SURGICAL TECHNIQUE: Skin incision at the hand with access to any anatomical structure. POSTOPERATIVE MANAGEMENT: Postoperative treatment depends on the disease and hand surgery performed.

Laparoscopic pectopexy: a follow-up cyclic biomechanical analysis determining time to functional stability.

INTRODUCTION: Pectopexy, a laparoscopic method for prolapse surgery, showed promising results in previous transient testing by this group. It was shown that a single suture, yielding an ultimate load of 35 N, was equivalent to continuous suturing. This was demonstrated in an in vitro cadaver study. This transient data were used to establish an elastic stress-strain envelope. It was now possible to proceed to dynamic in vitro analysis of this surgical method to establish time to functional stability. METHODS: Cyclic testing of this fixation method was performed on human female embalmed cadaver (cohort 1) and fresh, non-embalmed cadaver (cohort 2) pelvises. The testing envelope was 5-25 N at a speed of 1 mm/s. 100 load regulated cycles were applied. RESULTS: 100 cycles were completed with each model; no overall system failure occurred. Steady state, i.e., functional stability was reached after 14.5 (± 2.9) cycles for the embalmed group and after 19.1 (± 7.2) cycles for the non-embalmed group. This difference was statistically significant p = 0.00025. CONCLUSION: This trial showed in an in vitro cyclic testing of the pectopexy method that functional stability may be achieved after no more than 19.1 cycles of load exposure. When remaining within the established load envelope of below 25 N, patients do not need to fear global fixation failure. Testing did demonstrate differences in non-embalmed and embalmed cadaver testing. Embalmed cadaver testing tends to underestimate time to steady state by 26.3%.

Peroneal nerve location at the fibular head: an anatomic study using 3D imaging.

INTRODUCTION: Injuries to the peroneal nerve are a common complication in operative treatment of proximal tibial or fibular fractures. To minimize the risk of iatrogenic injury to the nerve, detailed knowledge of the anatomy of the peroneal nerve is essential. Aim of this study was to present a detailed description of the position and branching of the peroneal nerve based on 3D-images to assist preparation for surgical approaches to the fibular head and the tibial plateau. METHODS: The common peroneal nerve, the deep and the superficial peroneal nerve were marked with a radiopaque thread in 18 formalin-embalmed specimens. Three-dimensional X-ray scans were then acquired from the knee and the proximal lower leg in full extension of the knee. In 3D-reconstructions of these scans, distances of the common peroneal nerve and its branches to clearly defined osseous landmarks were measured digitally. Furthermore, the height of the branching of the common peroneal nerve was measured in relation to the landmarks. RESULTS: The mean distance of the common peroneal nerve at the level of the tibial plateau to its posterior osseous limitation was 7.92 ± 2.42 mm, and 1.31 ± 2.63 mm to the lateral osseous limitation of the tibia. In a transversal plane, distance of the common peroneal nerve branching was 27.56 ± 3.98 mm relative to the level of the most proximal osseous extension of fibula and 11.77 ± 6.1 mm relative to the proximal extension of the tibial tuberosity. The deep peroneal nerve crossed the midline of the fibular shaft at a distance of 22.14 mm ± 4.35 distally to the most proximal extension of the fibula, the superficial peroneal nerve at a distance of 33.56 mm ± 6.68. CONCLUSION: As the course of the peroneal nerve is highly variable in between individuals, surgical dissection for operative treatment of proximal posterolateral tibial or fibular fractures has to be done carefully. We defined an area were the peroneal nerve and its branches are unlikely to be found. However, specific safe zones should not be utilized due to the individual anatomic variation.

[Olecranon fractures]. / Olekranonfrakturen.

Olecranon fractures represent a common elbow injury and they are usually treated operatively. Depending on fracture morphology conservative therapy can be considered in geriatric patients. When surgical treatment is performed the anatomical features of the proximal ulna have to be taken into consideration. Tension band wiring is considered a standard procedure for simple fractures and provides good clinical results. Plate osteosynthesis is indicated for more complex fracture patterns. Nowadays, many surgeons prefer plate fixation over tension band wiring even for simple fractures as it leads to a more stable fixation. Both methods frequently require hardware removal for persisting soft tissue irritation. The use of modern low-profile plates could reduce the need for implant removal due to better soft tissue coverage. The available clinical data regarding low-profile plates are promising but limited.

[Elbow prostheses in rheumatic diseases]. / Ellenbogenprothese bei rheumatischen Erkrankungen.

When the elbow is destroyed due to rheumatic diseases, the joint can be replaced by a prosthesis and total arthroplasty. Improved pharmaceutical treatment for rheumatic diseases has, however, reduced the number of implantations in these patients. Reported 10-year survival rates of the implant currently achieve 81-90%.; however, due to limited long-term survival of the implant and high complication rates, total elbow arthroplasty should still be used with caution. Continuous technical improvements in the available prostheses and in surgical techniques could lead in the future to a decline in complications, such as aseptic loosening and infections.

[Total elbow arthroplasty in traumatic and post-traumatic bone defects]. / Ellenbogentotalendoprothetik bei traumatischen und posttraumatischen Knochendefekten.

Total elbow arthroplasty is currently most commonly carried out due to acute trauma or post-traumatic conditions. Bone defects are often present and must be considered in the (pre-)operative workup. The use of semi-constrained prostheses with a systematic cementing technique through a triceps-on approach leads to satisfying clinical results, however, the outcome is worse when compared with rheumatic patients.Primary total elbow arthroplasty for complex distal humerus fractures in the elderly patient or secondary implantation following failed conservative treatment or osteosynthesis represent possible indications for (post­)traumatic joint replacement. The condyles do not have to be reconstructed and the humerus can be shortened by 2-3 cm without sacrificing the functionality of the extensor apparatus. In the case of post-traumatic joint destruction and pronounced chronic instability following complex fractures of the proximal forearm - especially following terrible triad or Monteggia-like injuries - total elbow arthroplasty can be considered as a treatment option. The extensor apparatus must be reconstructed, and the implantation of the prosthesis must thus be combined with plate osteosynthesis of the ulna - if necessary. Chronic deformity should only be corrected as much as needed in order to avoid early aseptic loosening due to increased shearing forces and polyethylene wear.Massive bone loss is problematic and can be compensated with allografts or tumor prostheses. The results of these salvage procedures are less predictable, and complication rates increase significantly.

Suture button reconstruction of the central band of the interosseous membrane in Essex-Lopresti lesions: a comparative biomechanical investigation.

Surgical reconstruction of the interosseous membrane may restore longitudinal forearm stability in Essex-Lopresti lesions. This study aimed to compare the longitudinal stability of the intact forearm with a single-bundle and a double-bundle reconstruction of the central band of the interosseous membrane using digital image correlation with a three-dimensional camera system. Single and cyclic axial loading of eight fresh-frozen forearm specimens was carried out in the intact state, after creation of an Essex-Lopresti lesion, after a single-bundle and after a double-bundle reconstruction of the central band using a TightRope® (Arthrex GmbH, Munich, Germany) construct. Instability significantly increased after creation of an Essex-Lopresti lesion. The stability of intact specimens was similar to both reconstruction techniques. The results of this study suggest that TightRope® reconstruction of the central band restores longitudinal forearm stability. However, the single-bundle technique may be less reliable than double-bundle reconstruction. LEVEL OF EVIDENCE: Basic Science Study.

[Lateral ulnar collateral ligament reconstruction : A biomechanical analysis of posterolateral rotatory instability of the elbow]. / Laterale ulnare Kollateralbandplastik : Biomechanische Untersuchung zur posterolateralen Rotationsinstabilität des Ellenbogens.

BACKGROUND: Chronic posterolateral rotatory instability (PLRI) of the elbow is the result of an insufficiency of the lateral collateral ligament (LCL). Lateral ulnar collateral ligament (LUCL) reconstruction represents a well-established treatment method for PLRI. However, recurrent instability remains a problem. OBJECTIVES: The goal of this in-vitro study was to evaluate the posterolateral rotatory stability of the intact elbow, after sectioning of the LCL and after LUCL reconstruction with a triceps tendon autograft and double BicepsButton(TM) fixation. MATERIALS AND METHODS: Posterolateral rotatory stability of 6 fresh-frozen elbow specimens at a torque of 3 Nm was analyzed at 0, 45, 90 and 120° of flexion for the intact LCL, after sectioning of the LCL and after LUCL reconstruction. Moreover, cyclic loading (1000 cycles) of the intact specimens and after LUCL reconstruction was performed. RESULTS: The intact LCL and the LUCL reconstruction provided equal primary stability (0.250 ≤ p ≤ 0.888). Sectioning of the LCL significantly increased PLRI (p < 0.001). The stability of the intact specimens and after LUCL reconstruction did not differ after cyclic loading (p = 0.218). During cyclic loading, posterolateral rotation increased significantly more after LUCL reconstruction (3.2 ± 0.8°) when compared to the native LCL (2.0 ± 0.7°, p = 0.020). CONCLUSIONS: LUCL reconstruction with BicepsButton(TM) fixation provides comparable stability to the native LCL. Further clinical results are necessary to evaluate whether this technique can decrease the complication rate.

[The bare area of the proximal ulna : An anatomical study on optimizing olecranon osteotomy]. / Die Bare Area der proximalen Ulna : Eine anatomische Studie zur Optimierung der Olekranonosteotomie.

BACKGROUND: Olecranon osteotomy is an established approach for the treatment of distal humerus fractures. It should be performed through the bare area of the proximal ulna to avoid iatrogenic cartilage lesions. OBJECTIVES: The goal of this study was to analyze the anatomy of the proximal ulna with regard to the bare area and, thereby, to optimize the hitting area of the bare area when performing olecranon osteotomy. MATERIALS AND METHODS: The bare areas of 30 embalmed forearm specimens were marked with a radiopaque wire and visualized three-dimensionally with a mobile C­arm. By means of 3D reconstructions of the data sets, the following measurements were obtained: height of the bare area; span of the bare area-hitting area in transverse osteotomy; ideal angle for olecranon osteotomy to maximize the hitting area of the bare area; distance of the posterior olecranon tip to the entry point of the transverse osteotomy and the ideal osteotomy. RESULTS: The height of the bare area was 4.92 ± 0.81 mm. The hitting area of the transverse osteotomy averaged 3.73 ± 0.89 mm. The "ideal" angle for olecranon osteotomy was 30.7° ± 4.19°. The distance of the posterior olecranon tip to the entry point was 14.08 ± 2.75 mm for the transverse osteotomy and 24.21 ± 3.15 mm for the ideal osteotomy. The hitting area of the bare area in the ideal osteotomy was enhanced significantly when compared to the transverse osteotomy (p < 0.0001). CONCLUSIONS: This study provides guide values for correct osteotomy of the olecranon. Moreover, a 30° angulation of the osteotomy can significantly increase the hitting area of the bare area.

[Chronic ligamentous instability of the elbow]. / Chronische Bandinstabilitäten des Ellenbogengelenks.

BACKGROUND: Chronic ligamentous instability of the elbow is an important pathology as it is accompanied with pronounced dysfunction. Moreover, it represents an established risk factor for the development of osteoarthritis. Posterolateral rotatory instability (PLRI) caused by insufficiency of the lateral collateral ligament (LCL) is the most common type of chronic elbow instability and is usually a sequel of traumatic elbow dislocation. Chronic overload can lead to insufficiency of the ulnar collateral ligament (UCL) with subsequent valgus instability, especially in overhead athletes. DIAGNOSTICS: Subjective instability and recurrent elbow dislocations are not always the main symptoms but elbow instability is instead often characterized by pain and secondary joint stiffness. Many clinical tests are available yet eliciting them can be difficult and inconclusive. A "drop sign" on lateral radiographs as well as the detection of collateral ligament injuries and joint incongruity on MRI scans can support the suspected diagnosis. In some cases, instability can only be verified by diagnostic arthroscopy. TREATMENT: Reconstruction of the lateral ulnar collateral ligament (LUCL) for treatment of PLRI generally leads to good clinical results, yet recurrent instability remains an issue and has been reported in 8 % of cases. UCL reconstruction for chronic valgus instability leads to a return-to-sports rate of about 86 % in the overhead athlete. Ulnar neuropathy, which is seen in approximately 6 % of patients, represents the most common complication. On the rare occasion of multidirectional instability, the box-loop technique can be used for simultaneous reconstruction of the LUCL and UCL with a circumferential graft. 15 cases with promising results have been reported in literature thus far.