[Treatment of extensor tendon injuries of the hand]. / Behandlung von Strecksehnenverletzungen der Hand.

The extensor apparatus of the hand is a complex system consisting of extrinsic and intrinsic muscles, which in combination enable the individual extension of the fingers. Extensor tendon injuries of the hand are frequent injuries and the operative or conservative treatment options are determined by the localization and involvement of osseus structures. For an optimal outcome of the treatment of extensor tendon injuries, correct diagnostics and a consistent hand aftercare are absolutely essential. The crucial decision making regarding the further procedure starts with the initial patient treatment, ideally on the day of trauma.

[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.

[Mid- to long-term functional results after Bowers' hemiresection interposition arthroplasty of the distal radio-ulnar joint]. / Mittel- bis langfristige, funktionelle Ergebnisse nach Hemiresektion-Interpositions-Arthroplastik (nach Bowers) des distalen Radioulnargelenks.

BACKGROUND: Bowers' hemiresection interposition arthroplasty of the distal radio-ulnar joint has been performed for decades, mainly for the treatment of osteoarthritis of the distal radio-ulnar joint. However, long-term test results are sparse. OBJECTIVE: Evaluation of a homogeneous patient population following a mid- to long-term postoperative follow-up interval after hemiresection interposition arthroplasty. PATIENTS AND METHODS: Twenty-five patients were evaluated 77.2 (±34.6) months after surgical therapy with regard to range of motion, grip strength and pain level. The subjective and objective scores DASH (Disabilities of Arm, Shoulder, and Hand) and MMWS (modified Mayo Wrist Score) were collected. RESULTS: Wrist mobility is not worse than 10.4° in relation to all directions of wrist movement compared with the healthy opposite side. Coarse grip strength is reduced by an average of 5.8 kg compared with the opposite side. The pain level decreased on average from 8.2 preoperatively to 1.8 postoperatively. Postoperatively, 22 patients (88 %) had a stable distal radio-ulnar joint. At the time of follow-up DASH averaged 26.7 (±21.4) and the MMWS averaged 78 (±15.7). DISCUSSION: Hemiresection interposition arthroplasty is a reliable and safe surgical technique with good subjective and functional outcomes in the mid- to long-term.

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.

[Minimally invasive procedures in the early stages of trapeziometacarpal joint osteoarthritis : Denervation, arthroscopy and autologous fat transplantation]. / Minimal-invasive Verfahren im Frühstadium der Daumensattelgelenksarthrose : Denervierung, Arthroskopie, autologe Fetttransplantation.

BACKGROUND: Resection arthroplasty of the trapezium with or without tendon interposition is the standard procedure in the treatment of advanced, symptomatic thumb carpometacarpal joint osteoarthritis. Treatment recommendation in the early stages without visible or minimal radiographic changes is often difficult, especially when conservative treatment methods have already been exhausted. In these cases, there is the possibility of the minimally invasive methods of denervation, arthroscopic procedures and autologous fat transplantation. OBJECTIVES: Which minimally invasive procedures are available for the treatment of thumb carpometacarpal joint osteoarthritis and how is their value to be assessed? METHODS: The minimally invasive methods of denervation, arthroscopic procedures and autologous fat transplantation for the treatment of thumb carpometacarpal joint osteoarthritis are described and current results from the literature are discussed. RESULTS: Good results have been reported with all three procedures. However, the reports are almost exclusively based on retrospective studies with small numbers of patients, which lack control groups, so the results cannot be regarded as definitive. CONCLUSIONS: Denervation, arthroscopic procedures and autologous fat transplantation appear to be suitable methods in the early stages of thumb carpometacarpal joint osteoarthritis. Further studies, especially comparative randomised trials that report medium and long-term results, would allow further assessment of these methods.

Long-term outcome after arthroscopic debridement of Palmer type 2C central degenerative lesions of the triangular fibrocartilage complex.

PURPOSE: The purpose of this study was to report long-term objective and patient-reported outcome after arthroscopic debridement of central degenerative triangular fibrocartilage complex (TFCC) lesions. METHODS: A total of 17 patients with central degenerative TFCC (Palmer type 2C) lesions and ulnar positive variance who were treated by arthroscopic debridement were retrospectively reviewed. Mean follow-up was 8.8 years. Assessment facilitating the Modified Mayo Wrist score (MMWS), the Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH score), recording of pain level and of patient satisfaction, and radiological examination were done. RESULTS: Patients reached a pain level of 1.7 VAS, MMW score of 92, and DASH score of 22. No significant differences could be detected between the operated and the contralateral extremity regarding range of motion and grip strength for all patients. No perioperative complications occurred. CONCLUSION: Arthroscopic debridement of central degenerative TFCC lesions is safe, reliable, and efficacious even for ulnar positive variance. LEVEL OF EVIDENCE: Therapeutic IV.

The role of the transversal ligament on the atlantoaxial complex - Bending forces at C1/2 flexion limits in the elderly.

INTRODUCTION: Biomechanical functionality as well as trauma mechanisms of the atlantoaxial complex are still an issue of controversy. The transverse atlantal ligament is the strongest stabilizator. The present study aimed to analyze the bending forces of the transverse atlantal ligament and of the base of the odontoid in elderly specimens. METHODS: In this biomechanical study five cadaveric specimen with a mean age of 72 at death and bone mineral density measuring for 555.3 Hounsfield units on average were used. To analyze the strain of the transverse atlantal ligament and the dense base, strain gauges were used. A custom biomechanical setup was used to test each specimen at C1/2 flexion and the strain of the transverse atlantal ligament and the dens base (µm/m) were measured. FINDINGS: In four out of five, a rupture of the transverse atlantal ligament was observed, the mean force required for the ligament to fall was 175 N (min. 99.8 N; 249.2 N; SD 64.7) by a mean strain of 2102.9 µm/m (min. 1953.5 µm/m; max. 2272.3 µm/m; SD 189.7). In one specimen with the lowest Hounsfield units (155), the dens base fractured before the transverse atlantal ligament ruptured and no strain could be measured at the transversal ligament during movement afterwards. INTERPRETATION: The transverse atlantal ligament fails at an average of 175 N in the elderly, which is less than the value reported previously. In osteoporotic specimen the generated force to rupture the transverse atlantal ligament can fracture the dens itself.

Viscoelastic properties of the human A2 finger pulley.

INTRODUCTION: Biomechanical evaluation of the viscoelastic properties tissue deformation, stiffness, and maximum breaking load of the human A2 pulley. We hypothesized that the A2 pulleys of index, middle, and ring fingers exhibit no difference regarding the aforementioned biomechanical parameters. METHODS: Forty-one A2 pulleys of 14 upper extremities (8 body donors) were assessed. Cyclic and load-to-failure testing were performed. The biomechanical parameters tissue deformation during cyclic and load-to-failure testing, stiffness, and maximum breaking load were determined. RESULTS: No significant differences between the fingers could be detected regarding the biomechanical parameters. A significant negative correlation could be detected between stiffness and deformation of the pulley. Significant positive correlations could be identified between stiffness and maximum breaking load and between maximum breaking load and deformation of the pulleys. CONCLUSIONS: Assessment of the viscoelastic properties of the A2 finger pulley promotes precise diagnosis of pulley lesions and will help to optimize treatment.

[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.

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.

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.

[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.

[Revision surgery after failed (partial-) arthrodesis of the wrist]. / Revisionen nach fehlgeschlagenen (Teil­)Versteifungen am Handgelenk.

(Partial) arthrodeses of the wrist have been proven cornerstones to treat many lesions for decades, especially in the case of revision surgery. Four-corner, scapho-trapezo-trapezoidal (STT), radio-scapho-lunate (RSL) and total wrist fusions are very common techniques in hand surgery. However, even these proven surgical procedures have significant non-fusion rates. Prior to revising a failed arthrodesis, it is essential to analyse the latter failure precisely. A technically adequate revision is only feasible when based on a correct and meticulous analysis. The understanding of the biological processes and technical aspects of the implants are the basis for solving this issue.

[Tenolysis of extensor and flexor tendons of the hand]. / Tenolyse von Streck- und Beugesehnen an der Hand.

BACKGROUND: Unrestricted gliding of extensor and flexor tendons is essential for normal functioning of the hand. If tendon gliding is impaired, a restricted range of motion of finger joints and, finally, joint stiffness result. OBJECTIVES: To answer the questions about the causes of tenodesis in the hand, which examinations are most informative, how tenolysis is technically performed, and what results can be expected. METHODS: The reasons, examinations, surgical technique, and results of extensor and flexor tendon tenolysis are presented. RESULTS: Based on the data in the literature tenolysis of flexor tendons leads to range of motion that is only 50-60% of the preoperative range of motion. In about 20% of patients, deterioration as serious as secondary tendon rupture is observed. Meaningful results of extensor tendon tenolysis have not yet been published. CONCLUSIONS: Tenolysis of extensor and flexor tendons in the hand is a demanding surgical procedure, and in addition to detailed knowledge of anatomy and biomechanics, it requires sufficient experience-especially following the primary repair of tendon injuries. The earliest indication for tenolysis can occur at about 3 months, usually after 6 months, if continuous intensive hand therapy and splinting have not been successful. General and individual benefits and risks must be carefully weighed. The key to successful tenolysis is the patient's access to and unrestricted participation in competent postoperative treatment, ideally performed by a specialist in hand therapy, which may last for weeks or months.

[Surgical treatment of carpal tunnel syndrome: open release of the flexor retinaculum and hypothenar fat flap for revision surgery]. / Operative Behandlung des Karpaltunnelsyndroms: offene Retinakulumspaltung und Hypothenarfettlappenplastik beim Rezidiv.

OBJECTIVE: Decompression of the median nerve by complete release of the flexor retinaculum and the distal antebrachial fascia. In the case of revision surgery providing of a scar-free covering of the median nerve, if necessary. INDICATIONS: Carpal tunnel release is indicated for symptomatic patients with painful paraesthesia or neurological deficits after adequate diagnostic evaluation. The hypothenar fat flap is indicated in revision surgery if a sufficient nerve bed of the median nerve is needed and to restore nerve gliding. CONTRAINDICATIONS: General operative limitations. The hypothenar fat flap is not indicated in revision surgery if median nerve irritation is not caused by surrounding scaring but other reasons like tendonitis. SURGICAL TECHNIQUE: Proximal longitudinal incision of the palm. Subcutaneous dissection and incision of the palmar aponeurosis. Careful ulnar incision of the transverse carpal ligament. Considerate release of the distal and proximal parts of the retinaculum as well as the distal part of the antebrachial fascia. Exploration of the median nerve and palpation of the carpal tunnel and resection of compressive structures, if necessary. In case of revision surgery, if required, the hypothenar fat flap is raised. The fat flap is transposed without tension palmar to the median nerve and fixed to the radial side of the carpal tunnel. POSTOPERATIVE MANAGEMENT: Early functional mobilization. Immobilization for a short period is optional. After revision surgery and hypothenar fat flap, splinting for one week is recommended.

[Repair of the pronator quadratus muscle with a part of the brachioradialis muscle insertion in volar plate fixation of a distal radius fracture]. / Refixierung des Musculus pronator quadratus mit einem Teil des M.-brachioradialis-Ansatzes bei der palmaren Plattenosteosynthese einer distalen Radiusfraktur.

THE PROBLEM: Stable pronator quadratus repair following volar plate fixation of distal radius fractures with complete plate coverage is often difficult. THE SOLUTION: Detachment of the pronator quadratus muscle (PQ) with a strong rim of connective tissue consisting of a fibrous portion of the roof of the first extensor compartment and the volar limb of the brachioradialis muscle (BR) insertion; stable suture repair of the PQ with complete coverage of a volar plate after osteosynthesis of a distal radius fracture. SURGICAL TECHNIQUE: Radiopalmar approach between the radial artery and the flexor carpi radialis tendon to the PQ; sharp dissection below the radial artery onto the first extensor compartment, which is opened; retraction of the extensor pollicis brevis and abductor pollicis longus tendon; presentation of the BR insertion at the bottom of the first extensor compartment; incision of the BR insertion halfway to proximal and dissection of the volar limb at the transition to the free BR tendon; release of the PQ from the distal radius; after reduction and internal fixation repair of the PQ with complete coverage of the volar locking plate due to slight distal transposition. RESULTS: Pronator quadratus repair with a part of the brachioradialis muscle insertion is a reliable technique for coverage of a volar plate by slight distal transposition. In the repair of distal radius fractures, this may protect the finger flexor tendons against irritation and/or rupture.

[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.

[Anatomy of the metacarpophalangeal and proximal interphalangeal finger joint with respect to arthroplasty]. / Anatomie des Fingergrund- und -mittelgelenks unter Berücksichtigung der Endoprothetik.

BACKGROUND: Precise knowledge of the anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joint is the basis for both indication and implantation of a finger joint prosthesis. Currently available finger joint prostheses inadequately take into account individual, ethnological, gender, age, and side differences. They can remain compromised despite the possible combination of their components. OBJECTIVES: To elucidate which problems of finger joint arthroplasty exist due to the anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joints. METHODS: The anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joint are described, and the problems and solutions of finger joint arthroplasty are presented. RESULTS: Despite precise knowledge of the anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joint, not all problems of finger joint arthroplasty have been solved. However, a modular surface replacement appears promising for the proximal interphalangeal joint. CONCLUSIONS: Artificial joint replacement of the metacarpophalangeal and proximal interphalangeal joint is difficult with regard to morphology, small bone dimensions, complex biomechanics, and the strain of the hand. Further improvements, especially in design, should be achieved by exact anatomical imitation.

[Metacarpophalangeal joint replacement]. / Der Gelenkersatz der Fingergrundgelenke.

BACKGROUND: Arthroplasty of metacarpophalangeal (MCP) joints is crucial for patients with rheumatoid arthritis. Motion preserving therapies are mandatory for this joint, since loss of function of the MCP joint is detrimental. Many protheses or spacers have been introduced over the last 80 years, but most of them have been dismissed due to major complications. CURRENT PROCEDURES: Since the 1960s the Swanson spacer has been established as the reference standard for motion preserving procedures of the finger MCP joints. High fracture rates of the spacer do not seem to limit function and patient satisfaction after all. Current long-term studies show at least promising results for pyrolytic carbon protheses with respect to range of motion, survival, and revision rates in comparison to the Swanson spacer.