The aspects of sex, age and nationality in winter swimming performance.

OBJECTIVE: Winter swimming is a new sport discipline. Very little is known, however, about the sex differences, origin, participation and performance of the world's best winter swimmers. Therefore, the study aimed to investigate sex differences in performance and age. Furthermore, it should be determined which country has the fastest swimmers, the highest numbers of participants and the most successful age group athletes in winter swimming. SUBJECTS AND METHODS: A total of 6,477 results from the 25 m events of the IWSA (International Winter Swimming Association) World Cups from 2016-2020 was collected from the official website of IWSA. Data were analyzed using a generalized linear model (GLM) with a gamma probability distribution and identity link function. The 25 m events were carried out in head-up breaststroke style, freestyle and butterfly. The nationalities were grouped into six groups, the five nationalities with the highest number of participants in the 25 m competitions and one group with the other nationalities. The mean time of 25 m races by sex and country of the total sample was compared. For the top 10 comparisons, the best ten athletes from the six groups were selected. The mean time of each top 10 groups was compared by sex and nationality. RESULTS: Men were faster than women for all categories. Swimmers in age group 15-29 years were the fastest, where females were the fastest in age group 15-19 years and males in age group 20-29 years. Women from both Russia and Estonia and men from both Russia and China were the fastest. Both Russian and Chinese males were the fastest in all water categories in the top 10 section in the 25 m events. CONCLUSIONS: In summary, males were faster than females in the IWSA World Cups between 2016 and 2020. The age group of 15-29 years old athletes was the most successful while females had their age of peak performance earlier than males. Russian and Estonian males and Russian females were the overall fastest in the 25 m events in all water categories. Future studies should investigate the optimal anthropometric characteristics of male and female winter swimming sprint athletes and whether there are distinct areas in Russia, Estonia and China, where many international winter swimming athletes originate.

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.

[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.

[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.

[Biomechanical comparison of six different fixation techniques for treatment of metacarpal neck fractures]. / Biomechanischer Vergleich sechs verschiedener Fixationstechniken zur Versorgung von Halsfrakturen der Metakarpale.

PURPOSE: The purpose of this study was to evaluate the primary stability of commonly used fixation techniques for metacarpal neck fractures and to compare it with that of an innovative osteosynthesis device: IlluminOss™, the photodynamic bone stabilization system™. MATERIAL AND METHODS: Metacarpal neck fractures were created on the second to fifth metacarpal bones of 24 freshly frozen human cadavers using a band saw. Specimens were randomly assigned to one of six groups and treated with (1) K-wire fixation, (2) dorsal plating, (3) external fixation, (4) cross-threaded K­wire fixation, (5) IlluminOss™ and (6) locked IlluminOss™. In each group 16 specimens each underwent either monocyclic or polycyclic loading protocols. RESULTS: During monocyclic loading none of the specimens failed prior to a maximum deformation of 3 mm. With intramedullary K­wire fixation the mean loads were significantly lower than those of the other techniques. Mean loads causing 2 mm deformation with external fixation were significantly lower than those with dorsal plate osteosynthesis. The mean linear stiffness of the K­wire osteosynthesis was significantly lower than for the other fixation techniques and all methods of external fixation were significantly lower than dorsal plates. There were no significant differences with respect to the linear stiffness between the groups with dorsal plates, fragment fixation system (FFS), IlluminOss™ and locked IlluminOss™. During polycyclic testing the loss of resistance in dorsal plate osteosynthesis was significantly lower than with K­wire and IlluminOss™ fixation. No significant differences in loss of resistance could be shown between dorsal plate osteosynthesis, external fixation, FFS and locked IlluminOss™. CONCLUSION: In summary, IlluminOss™ can be used as an intramedullary stabilization system for treatment of metacarpal neck fractures. In combination with locking screws the biomechanical characteristics of IlluminOss™ are comparable to the other fixation techniques.

[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.

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.

[The proximal radioulnar joint in consideration of the distal radioulnar joint]. / Das proximale Radioulnargelenk unter Berücksichtigung des distalen Radioulnargelenks.

The movement of the forearm follows a complex interplay of three main components: the proximal and distal radioulnar joint and the interosseous membrane. Injuries to one or even all components have a huge impact on the integrity of this system. The Essex-Lopresti lesion presented a high challenge in clinical diagnostics as well as therapy. Reconstructions of the length and stability are essential for a satisfactory postoperative outcome. If a reconstruction of the radial head by osteosynthesis is not possible, a radial head prosthesis should be implanted in the case of longitudinal instability - avoiding overlapping and/or oversizing. The reconstruction of the interosseous membrane should be considered, as well as the assessment of the distal radioulnar joint and/or the triangular fibrocartilage complex. Various reconstruction options are available in this regard.

[Anatomy and biomechanics of the distal radioulnar joint]. / Anatomie und Biomechanik des distalen Radioulnargelenks.

BACKGROUND: The functionality of the upper extremity is decisively based on rotation of the forearm. The rotation depends on the extent of motion of the distal radioulnar joint. Rotation enables complete and focused usability of the hand in order to cope with daily activities. The configuration of the distal radioulnar joint has developed over millions of years of evolution. ANATOMIC CONDITIONS: The triangular fibrocartilage complex is the crucial stabiliser of the latter joint since osseous structures are limited. The palmar and dorsal radioulnar ligaments belong to this complex. The superficial and deep parts of the latter ligaments insert both centrically in accordance to the axis of rotation and eccentrically. This arrangement guarantees stability of the joint throughout pronosupination. The interosseous membrane is a further relevant stabiliser that guarantees sufficient load transmission from radius to ulna. The distal oblique bundle of the interosseous membrane is outstanding in this context. The pronator quadratus muscle is the relevant dynamic stabiliser of the distal radioulnar joint. Contraction of the muscle prevents diastasis of the joint. The deep head of the muscle is always activated during pronosupination.

[Diagnosis and treatment of degenerative disc lesions of the wrist]. / Diagnostik und Therapie der degenerativen Diskusläsion.

BACKGROUND: The triangular fibrocartilage complex (TFCC) widens the radiocarpal joint and takes part in load transmission from the carpus to the forearm. It is thereby prone to degenerative changes. The painful situation that can accompany degeneration is called ulnar impaction. DIAGNOSIS: Clinical examination helps differentiate between various causes of ulnar-sided wrist pain. Standard X­rays are needed to determine ulnar variance and stress radiographs can depict narrowing of the ulnocarpal joint space under load. MRI may prove degeneration of the TFCC itself or may indirectly confirm ulnar impaction in the presence of bone marrow edema in the ulnar head or at the proximal ulnar aspect of the lunate. TREATMENT: If conservative treatment fails to alleviate symptoms, arthroscopy may be indicated. On the one hand, this completes the diagnostic cascade, and, on the other hand, allows decompression of the ulnocarpal joint space by resection of the TFCC with partial resection of the ulnar head (wafer resection). In the case of ongoing pain, ulnar shortening sufficiently alleviates ulnar-sided wrist pain. Thereby, modern standardized operation techniques are safe enough to ensure bone healing at the osteotomy site. The aim of alleviating ulnar-sided wrist pain is mostly achieved if the correct treatment option is chosen.

[Ligamentous lesions and instability of the finger joints]. / Ligamentäre Verletzungen und Bandinstabilitäten der Fingergelenke.

Joint capsule and ligamentous lesions are common injuries of the upper extremities. Athletes are particularly inclined to suffer from these injuries. Clinical and radiological examinations are the cornerstone of an adequate treatment. Ultrasound-based diagnostics as a non-invasive and dynamic investigation method are gaining increasing relevance based on the development of high resolution probes. A correct interpretation of the findings is only feasible with a comprehensive knowledge of the anatomy. The most important goal is stability as a prerequisite for early active and passive motion with unrestricted range of motion.

Pathoanatomic Risk Factors for Instability and Adjacent Segment Disease in Lumbar Spine: How to Use Topping Off?

PURPOSE: The goal of this review is to identify criteria indicating implantation of hybrid system into lumbar spine and to evaluate general benefits of use. METHODS: A systematic review of literature was performed using current randomized clinical trials, reviews, and meta-analyses. Data sources included relevant literature of human studies identified through searches of Medline Library until May 2015. RESULTS: Predisposing factors for Adjacent Segment Disease (ASDi) are discussed in literature: laminar horizontalization, insufficiency of fascia thoracolumbalis, facet tropism, and facet sagittalization. Currently there is no evidence for topping off. There are only 12 studies and these have no consistent statements about use of a hybrid system for avoidance of ASDi. CONCLUSION: Hybrid instrumentation of lumbar spine, either with pedicle-based technique or additional spacer, might possibly prevent ASDi from developing in previously damaged segment adjacent to a fusion. Good clinical data proving effectiveness of this new implant technique is as yet unavailable. Thus, currently one must speak of an unevaluated procedure. Various radiological classifications can assist in making a reliable decision as to whether hybrid instrumentation is an appropriate choice of therapy. Pathoanatomical conditions of facet joints and laminae as well as preservation of sagittal balance must also be considered.

[Arthrodesis of the distal interphalangeal joint using the headless compression screw]. / Die Fingerendgelenkversteifung mit der Doppelgewindeschraube.

OBJECTIVE: Arthrodesis of the distal interphalangeal joint of the fingers and interphalangeal joint of the thumb in order to gain reliable stability and function. INDICATIONS: Primary and secondary osteoarthritis, rheumatoid arthritis, defect lesions, septic joint destruction, posttraumatic joint deviation, fatal joint instability, fatal tendon lesions. CONTRAINDICATIONS: Persistent infections (empyema, osteomyelitis, phlegmon), deficient soft tissue mantle, bone/screw mismatch. SURGICAL TECHNIQUE: Using Beasley's approach the extensor tendon is identified and sectioned. Incision of the collateral ligaments enables good exposition. Precise resection of the joint surfaces. An orthograde guidewire is place into the distal phalanx. After adjustment of the arthrodesis which is controlled using x­ray, the guide wire is drilled into the middle phalanx in retrograde fashion. An adequate headless compression screw is introduced via a transverse incision at the fingertip using the guide wire, the former screw is placed until sufficient compression is generated. POSTOPERATIVE MANAGEMENT: Finger splint reaching to the proximal interphalangeal joint for 4 weeks after arthrodesis, full weight bearing after 6 weeks. RESULTS: Seventeen patients were examined after arthrodesis of the distal interphalangeal joint using the headless compression screw. The arthrodesis proved to be reliable and safe with a low complication rate and a good functional outcome. The modified Mayo Wrist Score (MMWS) was on average 89 (range 55-100); the outcome parameter DASH (disabilities of arm, shoulder and hand) score was on average 27 (range 1-60).

[Percutaneous needle aponeurotomy for Dupuytren's contracture]. / Perkutane Nadelaponeurotomie bei Dupuytren-Kontraktur.

Dupuytren disease is a benign fibroproliferative disease of the palmar aponeurosis, which can cause considerable functional deficiencies for the person concerned. Partial aponeurectomy is the gold standard in primary surgery. Because it is minimally invasive and has short recovery and low complication rates, the importance of needle aponeurotomy under specific indications has been increasing in the last years. Needle aponeurotomy is a cost-effective treatment with low complication rates. The revision rate compared to partial aponeurectomy is higher. Under consideration of specified indications, needle aponeurotomy is an alternative treatment option.

A novel classification of screw placement accuracy in the cervical spine.

BACKGROUND: Goal of this study is to present an easily reproducible and reliable measurement to evaluate accuracy of screw placement in cervical spine. METHODS: Accuracy of cervical screw position was assessed in 52 patients treated with 163 screws. Each patient receiving pedicle, transarticular C1/2, lateral mass, or laminar screws and postoperative CT scan was included. Placement position was categorized in 5 grades: Grade 1 is ideal with pedicle wall perforation < 1 mm, grade 2 < 2 mm, grade 3 < 3 mm, and grade 4 < 4 mm. Grade 5 > 4 mm and/or obstruction of transverse foramen by more than half a screw diameter. Intraclass correlation coefficient (ICC) values were assessed for inter- and intraobserver reliability. RESULTS: The mode of individual evaluations was calculated to assign a single value to each screw. This yielded 89 grade 1 (54.6%), 48 grade 2 (29.4%), 14 grade 3 (8.6%), 3 grade 4 (1.8%), and 9 grade 5 (5.5%) screws. Intraobserver reliability ICC was 0.966 and 0.959 for measurements. Interobserver reliability ICC was 0.938. CONCLUSION: This study introduces a reliable classification of cervical spine instrumentation with various screw types. This should enable the use of a uniform and reproducible, and thus comparable classification for screw position in cervical spine.

[Should we use hip-ankle radiographs to assess the coronal alignment after total knee arthroplasty?]. / Ist die postoperative Ganzbeinaufnahme nach Knie-TEP-Implantation notwendig?

BACKGROUND: There is no consensus on whether hip-ankle radiographs or rather standardized a­p knee-radiographs should be used to assess implant position and coronal alignment after total knee arthroplasty (TKA). This study investigates whether implant position and alignment after TKA can reproducibly be assessed using a­p knee-radiographs rather than hip-ankle radiographs. MATERIALS AND METHODS: This study was performed on 100 weight-bearing hip-ankle radiographs after conventional primary TKA. The true mechanical and anatomical femorotibial angle as well as coronal implant position was assessed on hip-ankle radiographs. The radiographs were then cropped to 80, 60 and 40 % of the leg-length and tibial coronal implant position, and the anatomical axis and a surrogate mechanical axis were obtained. The difference in the alignment parameters between the hip-ankle radiographs were statistically compared with the cropped radiographs and the inter-observer correlation coefficient (ICC) was calculated. RESULTS: The ICC for measurement of the mechanical femorotibial angle was higher in hip-ankle radiographs (0.95) when compared with a radiograph cropped to 40 % (0.61). There was a significant difference in the mechanical femorotibial angle between hip-ankle radiographs and any cropped radiograph. However, there were no significant differences in coronal implant position and the anatomical femorotibial angle between hip-ankle radiographs and any cropped radiograph. CONCLUSIONS: We conclude that standard a­p knee-radiographs are insufficient to assess the mechanical alignment following TKA. However, standard a­p knee-radiographs are appropriate to assess the implant position when referenced against the anatomical axes. Weight-bearing hip-ankle radiographs should be questioned as a routine after TKA.

[Conservative treatment of nonspecific, chronic low back pain : Evidence of the efficacy - a systematic literature review]. / Konservative Therapie beim unspezifischen, chronischen Kreuzschmerz : Evidenz der Wirksamkeit - eine systematische Literaturanalyse.

OBJECTIVES: Non-specific chronic low back pain (NSCLBP): Which conservative therapy shows an evident effectiveness - A review of the current literature. MATERIALS AND METHODS: Our results are based on literature reviews of current randomised control studies, reviews and meta-analysis drawn from the Cochrane Library and Medline-Database between the years 2004 until 2015. German and English Studies were included. We focused on different conservative Treatments of NSCLBP, which are listed at, the NVL-Guidelines. Based on the given evidence we evaluated their effectiveness. RESULTS: As part of the review we identified 4657 Publications, 85 were included in this study. Therapeutic options such as bed rest, TENS, Massage, Spine Supports, Back Schools and Antidepressants showed no evident effectiveness. Injections, NSAR analgesic therapy, Thermotherapy and Opioid analgesic therapy indicated a short-time effectiveness. A long term success (> 6 weeks) however, can not be shown. Only the Movement therapy can, in the summation of the included studies, postulate an evident (Evidence Level I) long-term effect treating NSCLBP. Only a few therapy options indicate a significant evident effectiveness for treating NSCLBP conservatively. At short notice methods such as injection therapy, thermo-therapy and analgesic therapies with NSAR and/or opioids help coping the acute phase. In the long term only movement therapy seems to provide an evident effectiveness. In the case of therapy-refractory NSCLBP a multimodal therapy should be considered.

[Surgical decompression of the superficial radial nerve: Wartenberg syndrome]. / Die operative Dekompression des Ramus superficialis des Nervus radialis: Das Wartenberg-Syndrom.

OBJECTIVE: Open decompression of the superficial radial nerve is performed at the distal forearm in cases of circumscript entrapment. Broad-based entrapments can be treated by endoscopically assisted decompression. INDICATIONS: Entrapment of the nerve along its course between the brachioradialis and extensor carpi radialis longus muscles or tendons. Persistent neuropathic pain with Tinel's sign. Numbness distal to the entrapment in accordance to nerval innervation. Futile conservative treatment. Pathological electrophysiological findings. CONTRAINDICATIONS: Endogeneous neuropathy, bleeding disorders, anticoagulation medication. SURGICAL TECHNIQUE: Longitudinal skin incision at the Tinel's sign at the forearm. The subcutaneous tissue is dissected until forearm fascia is detected. The fascia is opened cautiously under direct visualization and the superficial radial nerve is identified. In cases of broad-based entrapments, endoscopically assisted decompression can be performed. The dissector with attached optical device is introduced proximally and distally. Blunt mobilization using the dissector and preparation with the Metzenbaum scissors release the superficial radial nerve sufficiently. POSTOPERATIVE MANAGEMENT: Bandaging allowing immediate motion, removal of sutures after 14 days, avoidance of excessive use for 2 weeks. RESULTS: Surgical decompression of the superficial radial nerve yields good to excellent results regarding pain reduction and sensory function.