The superior healing capacity of MRL tendons is minimally influenced by the systemic environment of the MRL mouse.

Murphy Roths Large mice (MRL) exhibit improved tendon healing and are often described as a "super-healer" strain. The underlying mechanisms that drive the superior healing response of MRL remain a controversial subject. We utilized a tendon transplantation model between MRL and "normal-healer" B6-mice to differentiate between the contribution of MRL's innate tendon and systemic environment to its improved healing capacity. Patellar tendons with a midsubstance punch injury were transplanted back into the same animal (autograft) or into an animal of the other strain (allograft). Findings at 4 weeks showed that the innate MRL tendon environment drives its improved healing capacity as demonstrated by improved stiffness and maximum load in MRL-grafts-in-B6-host-allografts compared to B6-autografts, and higher modulus in MRL-autografts compared to B6-graft-in-MRL-host-allografts. Groups with an MRL component showed an increase in pro-inflammatory cytokines in the 3 days after injury, suggesting an early enhanced inflammatory profile in MRL that ultimately resolves. A preserved range of motion of the knee joint in all MRL animals suggests a systemic "shielding effect" of MRL in regard to joint adhesiveness. Our findings 4-weeks post injury are consistent with previous studies showing tissue-driven improved healing and suggest that the systemic environment contributes to the overall healing process.

Sports-Related Concussion Is a Personalized Issue-Evaluation of Medical Assessment and Subjective Feeling of the Athlete in a German Level 1 Trauma Center.

Sports-related concussions (SRC) have developed into a highly discussed topic in sports medicine over the last few years and demonstrate a severe issue in the personalized treatment of patients. This retrospective cohort study investigated 86 patients with sports-related concussions in a level 1 trauma center, relating to the mechanism, symptoms, medical history, acute therapy including first assessment and the return to sport. The research is based on medical records as well as questionnaires six months after hospitalization. Loss of consciousness for under 30 min (41.2%), headache (36.5%) and amnesia (29.4%) were the most frequent symptoms when presenting in the emergency room. During the hospitalization, mainly headache and vertigo were documented. Most concussions occurred after incidents in equitation and cycling sports; the most common mechanism was falling to the ground with a subsequent impact (59.3%). At the time of discharge from hospital, in 13.4% of all cases, concussion symptoms were still documented in medical records, in contrast to 39.5% of the concerned athletes who reported symptoms for longer than 24 h, and 41.0% who reported ongoing post-concussion symptoms after six months. Concussions are difficult-to-treat disorders with a challenging diagnostic process and many symptoms in various values and levels of persistence. Therefore, a patient-involving treatment with a complaint-dependent return to sport process should be applied to concerned athletes.

Current Standards of Early Rehabilitation after Anterior Cruciate Ligament Reconstruction in German Speaking Countries-Differentiation Based on Tendon Graft and Concomitant Injuries.

Background: Although anterior cruciate ligament reconstruction (ACLR) is a well-established procedure and is standardly performed by orthopedic surgeons all over the world, there does not seem to be a standard protocol for early rehabilitation. The purpose of this study was to give answers to the following questions: (i) Does (a) the use of a specific tendon graft, and (b) potentially additional therapy of concomitant pathologies influence surgeons' choice of a distinct postoperative rehabilitation protocol after ACLR? (ii) To what extent do these rehabilitation recommendations differ? Methods: Retrospective analysis of currently used early rehabilitation protocols after ACLR in German-speaking countries (GER, AUT and SUI) was conducted. Rehabilitation criteria included weight bearing, range of motion (ROM), the utilization of braces, continuous passive/active motion therapy (CPM/CAM), rehabilitation training and sport-specific training. Tendon grafts were differentiated as hamstring (HAM) and bone−patellar tendon−bone grafts (BTB). Concomitant pathologies included meniscus injuries (+M) and unhappy triad injuries (+UTI). Results: Most of the surveyed protocols were differentiated according to the used tendon graft or additional therapy of concomitant injuries (ACLR-differentiated, n = 147 vs. ACLR without graft differentiation, n = 58). When comparing ACLR-HAM and ACLR-BTB, significant differences were found regarding weight bearing (p = 0.01), ROM (p = 0.05) and the utilization of braces (p = 0.03). Regarding ACLR+M, an overall significant decelerated rehabilitation could be detected. After ACLR+UTI-therapy, a significant delayed start to full weight bearing (p = 0.002) and ROM (p < 0.001) was found. Conclusions: Most orthopedic surgeons from German-speaking countries differentiate early rehabilitation after ACLR according to the tendon graft used and therapy of concomitant pathologies. No consensus about early rehabilitation after ACLR is available. However, tendencies for an accelerated rehabilitation after ACLR-BTB and a more restrained rehabilitation of multiple injured knees were detected.

Football-related injuries are the major reason for the career end of professional male football players.

PURPOSE: Little is known about the consequences of injuries on professional male football players' career and retirement period. The aim of this study is to investigate the impact of injuries that male professional football players endure during their career, reasons for the end of their career and the post-career phase of retirement. METHODS: In a retrospective cross-sectional cohort study, retired male professional football players of the German Bundesliga were investigated by a standardised questionnaire to analyse the history of injuries sustained during their professional football career, the reasons for ending their career, their current health status and their suggestions for future prevention strategies. RESULTS: Most of the 116 analysed players (n = 73 (62.9%)) stated an injury as the reason for ending their professional career. Relevant injuries were mainly located in the lower extremities (n = 587 (61.3%)) with a focus on the knee (p < 0.001) and ankle (p < 0.001). A significant majority of the participants who had retired due to injury described degenerative symptoms, such as pain or instability, and were diagnosed with osteoarthritis after retirement (p < 0.001). These players had also often been affected by symptoms of depression during their career, which had decreased significantly after retirement. Moreover, players who had not retired due to injury had significantly better overall health status and quality of life after retirement. CONCLUSION: Football-related injuries have a significant impact on the career end of professional male football players and their health status after retirement. Future prevention strategies need to particularly address injuries to the knees and ankles and to implement measures for preventing osteoarthritis after retirement. LEVEL OF EVIDENCE: Level III.

Knee Surgery during the COVID-19 Lockdown-Experiences of a Level-One Trauma Center in Germany.

BACKGROUND: Almost every sector in the health care is affected by the COVID-19 pandemic. Many studies already investigated the effect on different aspects in orthopedic and trauma care. However, the current literature lacks data regarding the consequence on daily surgical business. Thus, the aim of the present study was to analyze the development of knee-related pathologies and surgical procedures in a German university level-one trauma center during the lockdown phase and early lockdown phase to investigate the impact of the COVID-19 lockdown on orthopedic and trauma knee surgery. Material and Methods. The amount of knee joint surgeries performed during the high-peak COVID-19 crisis in the period of January to May 2020 was evaluated retrospectively and compared to the corresponding time periods of the previous years (2017-2019). RESULTS: The COVID-19 lockdown led to a significant decrease in the number of knee injuries in March and April 2020 by 83.3%. Surgical procedures were reduced by 84.8% during the same period. In May 2020, the number of knee joint procedures returned to an almost prepandemic level. The distribution of urgent and elective knee surgery changed to predominantly acute trauma care at the beginning of the COVID-19 lockdown and persisted through to May 2020. CONCLUSION: The COVID-19 pandemic had a high impact on emergency and elective knee surgery in a level-one trauma center in Germany during the lockdown phase. It also showed that a level-one trauma center in the German healthcare system is able to handle urgent trauma and orthopedic operations during a worldwide medical crisis and to return to a prepandemic level within a short phase.

3D-Analysis of the Proximal Humeral Anatomy Before and After Stemless Shoulder Arthroplasty-A Prospective Case Series Study.

BACKGROUND: Stemless shoulder arthroplasty (SSA) is used to anatomically reconstruct proximal humerus geometry and preserve proximal humerus bone stock. The current literature lacks 3D-analysis of pre- and postoperative proximal humeral anatomy after SSA. The aim of this study was to prospectively analyze the humeral head anatomy using a computer-assisted topography mapping technique after SSA in relation to the preoperative status and the contralateral (not affected) side. METHODS: Twenty-nine patients (mean age: 63.5 ± 11.7 years) affected by primary shoulder osteoarthritis and treated with SSA were included. Preoperative and postoperative CT scans of the affected and contralateral sites were analyzed regarding joint geometry. Clinical outcome was assessed by Constant and Disabilities of the Arm, Shoulder and Hand (DASH) score shortly before and one year after surgery. RESULTS: Clinical outcome improved significantly. No correlation between clinical outcome and the evaluated anatomical parameters was found. There was a significant decrease of the humeral head height (p < 0.01) and radius (p = 0.03) in the preoperative versus the postoperative joint geometry. The comparison to the contralateral site showed also a significant decrease of the humeral head height (p < 0.01). All other parameters showed no significant differences. CONCLUSION: Proximal humeral anatomy can be almost anatomically reconstructed by SSA. Solely the humeral head height differs significantly to the preoperative as well as contralateral morphology.

Are There Any Red Flag Injuries in Severely Injured Patients in Older Age?

INTRODUCTION: Severely injured elderly patients pose a significant burden to trauma centers and, compared with younger patients, have worse prognoses and higher mortality rates after major trauma. The objective of this study was to identify the etiological mechanisms that are associated with severe trauma in elderly patients and to detect which injuries correlate with high mortality in elderly patients. METHODS: Using a prospect cohort study model over an 11-year period, severely injured patients (ISS ≥ 16) were divided into two age groups (Group 1: 18-64; Group 2: 65-99 years). A comparison of the groups was conducted regarding injury frequency, trauma mechanism, distribution of affected body parts (AIS and ISS regions) and injury related mortality. RESULTS: In total, 1008 patient were included (Group 1: n = 771; Group 2: n = 237). The most relevant injury in elderly patients was falling from low heights (<3 m) in contrast to traffic accident in young patients. Severely injured patients in the older age group showed a significantly higher overall mortality rate compared to the younger group (37.6% vs. 11.7%; p = 0.000). In both groups, the 30-day survival for patients without head injuries was significantly better compared to patients with head injuries (92.7% vs. 85.3%; p = 0.017), especially analyzing elderly patients (86.6% vs. 58.6%; p = 0.003). The relative risk of 30-day mortality in patients who suffered a head injury was also higher in the elderly group (OR: Group 1: 4.905; Group 2: 7.132). CONCLUSION: In contrast to younger patients, falls from low heights (<3 m) are significant risk factors for severe injuries in the geriatric collective. Additionally, elderly patients with an ISS ≥ 16 had a significantly higher mortality rate compared to severe injured younger patients. Head injuries, even minor head traumata, are associated with a significant increase in mortality. These findings will contribute to the development of more age-related therapy strategies in severely injured patients.

Comprehensive treatment algorithm for atlanto-axial rotatory fixation (AARF) in children.

BACKGROUND: Atlanto-axial rotatory fixation (AARF) is an uncommon condition in children presenting with torticollis. Many studies have elaborated on the diagnostic sequence of AARF. However, there is no consensus for the algorithm of management of AARF. METHODS: This study proposes to provide a comprehensive step-by-step guideline which aims to achieve and retain anatomic reduction of the atlanto-axial joint (AAJ). We recommend a 'therapeutic crescendo': closed reduction and immobilization in a rigid cervical collar (step I). In cases of re-dislocation, a second attempt of closed reduction and immobilization in a Halo-jacket (step II). Cases of recurrent dislocations due to persistent instability require open reduction and internal fixation. We present a new surgical technique of transverse suture transfixation (TSF) of C1/C2 (step III). Alternatively, a dorsal stabilization of C1/C2 is indicated after open reduction (step IV). 13 patients with radiologically confirmed AARF were included in this study. These patients were treated as per the above mentioned algorithm. All these patients were serially evaluated with a minimum follow-up of 1 year. RESULTS: Clinical data of 10/13 patients were available for follow-up evaluation at mean 4.6 years after the onset of symptoms. Two patients were managed surgically. We recorded good clinical results in all patients treated according to the algorithm. CONCLUSIONS: AARF is a subacute pediatric emergency. Reduction and maintenance of joint congruency of the AAJ are the treatment goals. The comprehensive therapeutic algorithm presented in this study is applicable in patients with AARF to achieve excellent long-term results. LEVEL OF EVIDENCE: IV, Retrospective cohort study. TRIAL REGISTRATION NUMBER: Clinical Trial Registry University of RegensburgZ-2014-0453-4. Registered 01 December 2014.

Changes of Material Elastic Properties during Healing of Ruptured Achilles Tendons Measured with Shear Wave Elastography: A Pilot Study.

Therapy options for ruptured Achilles tendons need to take into account the right balance of timing, amount and intensity of loading to ensure a sufficient biomechanical resilience of the healing tendon on the one hand, and to enable an adequate tensile stimulus on the other hand. However, biomechanical data of human Achilles tendons after rupture during the separate healing stages are unknown. Shear wave elastography is an ultrasound technique that measures material elastic properties non-invasively, and was proven to have a very good correlation to biomechanical studies. Taking advantage of this technology, 12 patients who suffered from an acute Achilles tendon rupture were acquired and monitored through the course of one year after rupture. Nine of these patients were treated non-operatively and were included for the analysis of biomechanical behaviour. A significant increase of material elastic properties was observed within the first six weeks after trauma (up to 80% of baseline value), where it reached a plateau phase. A second significant increase occurred three to six months after injury. This pilot study suggests a time correlation of biomechanical properties with the biological healing phases of tendon tissue. In the reparative phase, a substantial amount of biomechanical resilience is restored already, but the final stage of biomechanical stability is reached in the maturation phase. These findings can potentially be implemented into treatment and aftercare protocols.

Murine patellar tendon transplantation requires transosseous cerclage augmentation - development of a transplantation model for investigation of systemic and local drivers to healing.

BACKGROUND: Tendon injuries are common musculoskeletal injuries that heal with scar tissue formation, often achieving reduced biomechanical and functional properties. The murine patellar tendon is a research tool that holds potential for investigating tendon healing and can be useful for exploring therapeutic strategies. Since healing is a complex process that results from the collaboration between the systemic and local tissue environment, a murine tendon transplantation model that can be applied to transgenic mice and genetic mutants would allow isolation of systemic versus local tendon factors in driving effective tendon healing. Preliminary studies have shown that transplantation with simple tendon sutures results in a proximalization of the patellar bone due to the involuntary quadriceps muscle force leading to tearing of the graft and failure of the knee extensor mechanism. To avoid this elongation of the graft, two cerclage techniques for murine patellar tendon transplantation were introduced and validated. METHODS: Three developed surgical techniques (no-cerclage-augmentation (NCA)), transfascial suture cerclage with encirclement of the patellar tendon (TFSC), and dual-cerclage-augmentation with a transosseous bone-to-bone cerclage through the patella bone and an additional musculotendinous cerclage (DCA)) were compared at 4 and 8 weeks macroscopically in regards to graft continuity, cerclage integrity, gap formation, and radiologically by measuring the patello-tibial distance and using a patella bone position grading system. RESULTS: The NCA group showed complete failure at 5-7 days after surgery. The TFSC has led to 69% functional failure of the cerclage. In contrast, the DCA with a has led to 78% success with improvement in patellar bone position and a similar patello-tibial distance to the naïve contralateral murine knees over the time period of 8 weeks. CONCLUSIONS: This study shows that a bone-to-bone cerclage is necessary to maintain a desired graft length in murine patellar tendon models. This surgery technique can serve for future graft trans- and implantations in the murine patellar tendon.

Analysis of 213 currently used rehabilitation protocols in foot and ankle fractures.

INTRODUCTION: Fractures of the ankle, hind- and midfoot are amongst the five most common fractures. Besides initial operative or non-operative treatment, rehabilitation of the patients plays a crucial role for fracture union and long term functional outcome. Limited evidence is available with regard to what a rehabilitation regimen should include and what guidelines should be in place for the initial clinical course of these patients. This study therefore investigated the current rehabilitation concepts after fractures of the ankle, hind- and midfoot. METHODS: Written rehabilitation protocols provided by orthopedic and trauma surgery institutions in terms of recommendations for weight bearing, range of motion (ROM), physiotherapy and choice of orthosis were screened and analysed. All protocols for lateral ankle fractures type AO 44A1, AO 44B1 and AO 44C1, for calcaneal fractures and fractures of the metatarsal as well as other not specific were included. Descriptive analysis was carried out and statistical analysis applied where appropriate. RESULTS: 209 rehabilitation protocols for ankle fractures type AO 44B1 and AO 44C1, 98 for AO 44A1, 193 for metatarsal fractures, 142 for calcaneal fractures, 107 for 5(th) metatarsal base fractures and 70 for 5(th) metatarsal Jones fractures were evaluated. The mean time recommended for orthosis treatment was 6.04 (SD 0.04) weeks. While the majority of protocols showed a trend towards increased weight bearing and increased ROM over time, the best consensus was noted for weight bearing recommendations. CONCLUSION: Our study shows that there exists a huge variability in rehabilitation of fractures of the ankle-, hind- and midfoot. This may be contributed to a lack of consensus (e.g. missing publication of guidelines), individualized patient care (e.g. in fragility fractures) or lack of specialization. This study might serve as basis for prospective randomized controlled trials in order to optimize rehabilitation for these common fractures.