[Traumatic brain injuries in winter sports : An overview based on the winter sports skiing, snowboarding and ice hockey]

In winter sports, skiers, snowboarders and ice hockey players have the highest risk of traumatic brain injuries (TBI). In skiing/snowboarding severe TBIs are of concern; in ice hockey, repetitive minor TBIs are frequent. The main causes of TBI in recreational skiing are collisions with trees; in professionals falls due to technical or tactical mistakes are the main causes. In ice hockey 10-15% of all injuries are due to a sports-related concussion (SRC), mostly caused by player-opponent contact. The pathomechanism in TBI is a combination of rotational and linear acceleration during head impact, which causes a diffuse axonal injury. Long-term complications such as neurodegenerative diseases and functional deficits are of relevance. Prevention by wearing helmets is effective, but less effective in TBI/SRC than in focal injuries.

Injury incidence and specific injury patterns in app-based bodyweight training (Freeletics): results of an international survey with 3668 participants

Background

The aim of this study was to analyze incidences and sport-specific injury patterns among users of a bodyweight-based training method instructed by a smartphone app (Freeletics Bodyweight App).

Methods

An online questionnaire based on current validated epidemiological observation methods was designed using the statistic website Surveymonkey. Subscribers of the Freeletics Bodyweight App were contacted via an online link. Injury incidence, defined as an event leading to a training pause of at least 1 day, was recorded. The type of injury was reported and classified. Furthermore, all participants were asked whether they recognized any positive or negative effects on their subjective health status. The collected data were analyzed using Surveymonkey statistic services.

Results

A total of 4365 Freeletics users responded to the questionnaire, 3668 completed forms were subject of further investigation. The injury period prevalence reported by users of the Freeletics App was 24% in men and 21% in women. The most frequently reported site of injury was the shoulder (29%) and the knee joint (28%), with strains (28.5%) and other muscle injuries (14.4%) being the most frequently reported types of injuries. An injury incidence rate of 4.57 per 1000 h was calculated, with injuries occurring less frequently in experienced users. Most participants reported a distinct positive effect of the app-based training on their health status.

Conclusion

In comparison to other sports activities app-based bodyweight training is associated with a comparably low injury period prevalence. The vast majority of injuries were reported to have resolved within one week.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13102-022-00525-y.

Orthotic treatment of idiopathic toe walking with a lower leg orthosis with circular subtalar blocking

BACKGROUND

There is no universally accepted treatment standard for idiopathic toe walking patients (ITW) in the current literature. None of the established methods provide homogenous satisfying results. In our department we treat ITW patients with lower leg orthoses with a circular foot unit for a total of 16 weeks. In this study we reviewed our database to evaluate the success of our treatment protocol for a 24 months follow up period.

RESULTS

Twenty-two patients were included in this study. Age at the beginning of treatment was 7.0 years +/- 2.9 (range 2.5-13.1). Percentage of ITW at the beginning of treatment according to the perception of the parents was 89% +/- 22.2 (range 50-100). Immediately after the treatment with our device, percentage of ITW dropped to 11% +/- 13.2 (range 0-50). After 12 months, 73% of the patients (16/22) walked completely normal or showed ITW less than 10% of the day. After 24 months, 64% of the patients kept a normal gait (14/22).

CONCLUSION

This study provides evidence that the treatment of idiopathic toe walking with lower leg orthoses with a circular foot unit results in satisfying long-term results in two thirds of the patients.

Is unilateral lower leg orthosis with a circular foot unit in the treatment of idiopathic clubfeet a reasonable bracing alternative in the Ponseti method? Five-year results of a supraregional paediatric-orthopaedic centre

Background

In the Ponseti treatment of idiopathic clubfoot, children are generally provided with a standard foot abduction orthosis (FAO). A significant proportion of these patients experience irresolvable problems with the FAO leading to therapeutic non-compliance and eventual relapse. Accordingly, these patients were equipped with a unilateral lower leg orthosis (LLO) developed in our institution. The goal of this retrospective study was to determine compliance with and the efficacy of the LLO as an alternative treatment measure. The minimum follow-up was 5 years.

Results

A total of 45 patients (75 ft) were retrospectively registered and included in the study. Compliance with the bracing protocol was 91% with the LLO and 46% with the FAO. The most common problems with the FAO were sleep disturbance (50%) and cutaneous problems (45%). Nine percent of patients experienced sleep disturbance, and no cutaneous problems occurred with the LLO. Thirteen percent of patients being treated with an FAO until the age of four (23 patients; 40 ft) underwent surgery because of relapse, defined by rigid recurrence of any of the components of a clubfoot. Fourteen percent of patients being treated with an LLO (22 patients; 35 ft), mostly following initial treatment with an FAO, experienced recurrence.

Conclusion

Changing from FAO to LLO at any point during treatment did not result in an increased rate of surgery and caused few problems.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2160-1) contains supplementary material, which is available to authorized users.

The natural alpha angle of the femoral head-neck junction

Aims

Asphericity of the femoral head-neck junction is common in cam-type femoroacetabular impingement (FAI) and usually quantified using the alpha angle on radiographs or MRI. The aim of this study was to determine the natural alpha angle in a large cohort of patients by continuous circumferential analysis with CT.

Methods

CT scans of 1312 femurs of 656 patients were analyzed in this cross-sectional study. There were 362 men and 294 women. Their mean age was 61.2 years (18 to 93). All scans had been performed for reasons other than hip disease. Digital circumferential analysis allowed continuous determination of the alpha angle around the entire head-neck junction. All statistical tests were conducted two-sided; a p-value < 0.05 was considered statistically significant.

Results

The mean maximum alpha angle for the cohort was 59.0° (sd 9.4). The maximum was located anterosuperiorly at 01:36 on the clock face, with two additional maxima of asphericity at the posterior and inferior head-neck junction. The mean alpha angle was significantly larger in men (59.4°, sd 8.0) compared with women (53.5°, sd 7.4°; p = 0.0005), and in Caucasians (60.7°, sd 9.0°) compared with Africans (56.3°, sd 8.0; p = 0.007) and Asians (50.8°, sd 7.2; p = 0.0005). The alpha angle showed a weak positive correlation with age (p < 0.05). If measured at commonly used planes of the radially reconstructed CT or MRI, the alpha angle was largely underestimated; measurement at the 01:30 and 02:00 positions showed a mean underestimation of 4° and 6°, respectively.

Conclusion

This study provides important data on the normal alpha angle dependent on age, gender, and ethnic origin. The normal alpha angle in men is > 55°, and this should be borne in mind when making a diagnosis of cam-type morphology. Cite this article: Bone Joint J 2018;100-B:570–8.

[Hip dislocation after revision arthroplasty : Risk assessment and treatment strategies]

With a dislocation rate of up to 35% after revision total hip arthroplasty (THA), instability is one of the major causes why this procedure fails. Independent factors for patients at risk are age, sex, and the type of revision needed. The surgical approach, implant choice, and positioning of the components are factors that the surgeon can influence to keep the dislocation rate low. Large femoral heads or double mobility (DM) cups can increase the stability of the joint. After detailed failure analysis, targeted use of different technical innovations enhances stability in revision THA and prevents further revisions.

[Importance of revision- and tumor-endoprosthetics in the treatment of periprosthetic fractures of the lower extremity]

Periprosthetic fractures of hip and knee prostheses are gaining clinical significance due to the increasing numbers of of primary arthroplasties. Additionally, these fractures are often associated with poor bone quality or present in patients after multiple revision procedures and concomitant excessive bone defects precluding those patients to be adequately treated by conventional osteosynthesis. Revision implants provide a wide range of options for the treatment of these fractures in order to achieve good clinical results. In the acetabular region cavitary defects associated with periprosthetic fractures can be treated by the use of megacups. Extensive segmental defects and pelvic discontinuity necessitate the use of cups with additional iliac support or even customized implants. Proximal femoral fractures can usually be fixed with modular stems and diaphyseal anchorage. Periprosthetic knee joint fractures can be treated with revision implants with modular sleeves or augment-combinations allowing sufficient bridging of bony defects. Functional reconstruction or refixation of the extensor mechanism is of crucial importance.

Enoxaparin and rivaroxaban have different effects on human mesenchymal stromal cells in the early stages of bone healing

Objectives

Venous thromboembolism (VTE) is a major potential complication following orthopaedic surgery. Subcutaneously administered enoxaparin has been used as the benchmark to reduce the incidence of VTE. However, concerns have been raised regarding the long-term administration of enoxaparin and its possible negative effects on bone healing and bone density with an increase of the risk of osteoporotic fractures. New oral anticoagulants such as rivaroxaban have recently been introduced, however, there is a lack of information regarding how these drugs affect bone metabolism and post-operative bone healing.

Methods

We measured the migration and proliferation capacity of mesenchymal stem cells (MSCs) under enoxaparin or rivaroxaban treatment for three consecutive weeks, and evaluated effects on MSC mRNA expression of markers for stress and osteogenic differentiation.

Results

We demonstrate that enoxaparin, but not rivaroxaban, increases the migration potential of MSCs and increases their cell count in line with elevated mRNA expression of C-X-C chemokine receptor type 4 (CXCR4), tumor necrosis factor alpha (TNFα), and alpha-B-crystallin (CryaB). However, a decrease in early osteogenic markers (insulin-like growth factors 1 and 2 (IGF1, IGF2), bone morphogenetic protein2 (BMP2)) indicated inhibitory effects on MSC differentiation into osteoblasts caused by enoxaparin, but not by rivaroxaban.

Conclusions

Our findings may explain the adverse effects of enoxaparin treatment on bone healing. Rivaroxaban has no significant impact on MSC metabolism or capacity for osteogenic differentiation in vitro.

Cite this article: Dr H. Pilge. Enoxaparin and rivaroxaban have different effects on human mesenchymal stromal cells in the early stages of bone healing. Bone Joint Res 2016;5:95–100. DOI: 10.1302/2046-3758.53.2000595.

[Synovial biomarkers for differential diagnosis of painful arthroplasty]

BACKGROUND

The diagnosis and treatment of periprosthetic joint infection (PJI) remain true clinical challenges. PJI diminishes therapeutic success, causes dissatisfaction for the patient and medical staff, and often requires extensive surgical revision(s). At the present time, an extensive multimodal algorithmic approach is used to avoid time- and cost-consuming diagnostic aberrations. However, especially in the case of the frequent and clinically most relevant "low-grade" PJI, the current diagnostic "gold standard" has reached its limits.

EVALUATION

Synovial biomarkers are thought to close this diagnostic gap, hopefully enabling the safe differentiation among aseptic, (chronic) septic, implant allergy-related and the arthrofibrotic genesis of symptomatic arthroplasty. Therefore, joint aspiration for obtaining synovial fluid is preferred over surgical synovial tissue biopsy because of the faster results, greater practicability, greater patient safety, and lower costs. In addition to the parameters synovial IL-6, CRP, and leukocyte esterase, novel biomarkers such as antimicrobial peptides and other proinflammatory cytokines are currently highlighted because of their very high to excellent diagnostic accuracy.

CONCLUSION

Independent multicenter validation studies are required to show whether a set of different innovative synovial fluid biomarkers rather than a few single parameters is favorable for a safe "one-stop shop" differential diagnosis of PJI.

Function of the extensor mechanism of the knee after using the ‘patellar-loop technique’ to reconstruct the patellar tendon when replacing the proximal tibia for tumour

The aim of this study was to analyse the gait pattern, muscle force and functional outcome of patients who had undergone replacement of the proximal tibia for tumour and alloplastic reconstruction of the extensor mechanism using the patellar-loop technique.

Between February 1998 and December 2009, we carried out wide local excision of a primary sarcoma of the proximal tibia, proximal tibial replacement and reconstruction of the extensor mechanism using the patellar-loop technique in 18 patients. Of these, nine were available for evaluation after a mean of 11.6 years (0.5 to 21.6). The strength of the knee extensors was measured using an Isobex machine and gait analysis was undertaken in our gait assessment laboratory. Functional outcome was assessed using the American Knee Society (AKS) and Musculoskeletal Tumor Society (MSTS) scores.

The gait pattern of the patients differed in ground contact time, flexion heel strike, maximal flexion loading response and total sagittal plane excursion. The mean maximum active flexion was 91° (30° to 110°). The overall mean extensor lag was 1° (0° to 5°). The mean extensor muscle strength was 25.8% (8.3% to 90.3%) of that in the non-operated leg (p < 0.001). The mean functional scores were 68.7% (43.4% to 83.3%) (MSTS) and 71.1 (30 to 90) (AKS functional score).

In summary, the results show that reconstruction of the extensor mechanism using this technique gives good biomechanical and functional results. The patients’ gait pattern is close to normal, except for a somewhat stiff knee gait pattern. The strength of the extensor mechanism is reduced, but sufficient for walking.

Cite this article: Bone Joint J 2015;97-B:1063–9.

[Characteristics of 200 patients with suspected implant allergy compared to 100 symptom-free arthroplasty patients]

BACKGROUND

Data on implant allergies are incomplete; therefore, we compared the data on allergy history, patch test (PT) and lymphocyte transformation test (LTT) results in a patient series from the Munich implant allergy outpatient department with symptom-free arthroplasty patients.

PATIENTS AND METHODS

In this study 200 arthroplasty patients with complaints involving the prosthesis (130 female, 187 knee and 13 hip prostheses) and in parallel 100 symptom-free patients (75 female, 47 knee and 53 hip prostheses) were investigated. A questionnaire-aided history including implant type, cementing, intolerance of dental materials, atopy, cutaneous metal intolerance (CMI) and PT, including a standard series with Ni, Co, Cr, seven bone cement components, including gentamicin and benzoyl peroxide and LTT for Ni, Co and Cr.

RESULTS

In the knee arthroplasty patients with complaints 9.1% showed dental material intolerance, 23.5% atopy, 25.7% CMI, 18.2% metal allergies, 7.4% gentamicin allergy and 27.8% positive metal LTT (mostly to Ni). In symptom-free patients 0% showed dental material intolerance, 19.1% atopy, 12.8% CMI, 12.8% metal allergy, 0% gentamicin allergy and 17% positive metal LTT.

CONCLUSIONS

Characteristics of the patients with complaints were increased intolerance of dental materials, higher rates of atopy, CMI, metal and gentamicin allergy and LTT reactivity.

Irreversible muscle damage in bodybuilding due to long-term intramuscular oil injection

Intramuscular oil injections generating slowly degrading oil-based depots represent a controversial subject in bodybuilding and fitness. However they seem to be commonly reported in a large number of non-medical reports, movies and application protocols for 'site-injections'. Surprisingly the impact of long-term (ab)use on the musculature as well as potential side-effects compromising health and sports ability are lacking in the medical literature. We present the case of a 40 year old male semi-professional bodybuilder with systemic infection and painful reddened swellings of the right upper arm forcing him to discontinue weightlifting. Over the last 8 years he daily self-injected sterilized sesame seed oil at numerous intramuscular locations for the purpose of massive muscle building. Whole body MRI showed more than 100 intramuscular rather than subcutaneous oil cysts and loss of normal muscle anatomy. 2-step septic surgery of the right upper arm revealed pus-filled cystic scar tissue with the near-complete absence of normal muscle. MRI 1 year later revealed the absence of relevant muscle regeneration. Persistent pain and inability to perform normal weight training were evident for at least 3 years post-surgery. This alarming finding indicating irreversible muscle mutilation may hopefully discourage people interested in bodybuilding and fitness from oil-injections. The impact of such chronic tissue stress on other diseases like malignancy remains to be determined.

[Replacement of femoral hip prostheses]

Femoral revision of total hip arthroplasty is a technically demanding procedure. Therefore, accurate preoperative planning is essential for good clinical results. With many reconstruction methods available, the decision-making process can be complex. Well established classification systems can facilitate preoperative planning. At the time of revision surgery appropriate implants and instruments have to be available ensuring the possibility of managing operative complications. Primary goals of revision arthroplasty are restoration of the physiological joint biomechanics and primary stable fixation of the revision implant. In consideration of possible repeat revision surgery, cementless stem fixation should be preferred. Modular stems provide significant flexibility in restoring the center of rotation. Depending on the pre-existing femoral defect, osseous grafts can be necessary.The scope and classification systems of femoral osseous defects in revision arthroplasty will be discussed and different treatment options will be outlined, which guide the surgeon in selecting an appropriate method of reconstruction.