Primary stability of the Activ L® intervertebral disc prosthesis in cadaver bone and comparison of the keel and spike anchoring concept.

BACKGROUND: High primary stability is the key prerequisite for safe osseointegration of cementless intervertebral disc prostheses. The aim of our study was to determine the primary stability of intervertebral disc prostheses with two different anchoring concepts - keel and spike anchoring. METHODS: Ten ActivL intervertebral disc prostheses (5 x keel anchoring, 5 x spike anchoring) implanted in human cadaver lumbar spine specimens were tested in a spine movement simulator. Axial load flexion, extension, left and right bending and axial rotation motions were applied on the lumbar spine specimens through a defined three-dimensional movement program following ISO 2631 and ISO/CD 18192-1.3 standards. Tri-dimensional micromotions of the implants were measured for both anchor types and compared using Student's T-test for significance after calculating 95 % confidence intervals. RESULTS: In the transverse axis, the keel anchoring concept showed statistically significant (p < 0.05) lower mean values of micromotions compared to the spike anchoring concept. The highest micromotion values for both types were observed in the longitudinal axis. In no case the threshold of 200 micrometers was exceeded. CONCLUSIONS: Both fixation systems fulfill the required criteria of primary stability. Independent of the selected anchorage type an immediate postoperative active mobilization doesn't compromise the stability of the prostheses.

Intramedullary nailing as a safe and efficient treatment option for all types of displaced proximal humeral fractures in geriatric patients: A retrospective evaluation of 49 patients treated with the new Targon PH+ nail.

BACKGROUND: Implant specific complications and outcome for the use of proximal humeral nails in different fracture types are not well described. OBJECTIVE: Evaluation of adverse effects and outcome of patients treated with the new Targon PH+ implant for proximal humeral fractures in a geriatric population. METHODS: A consecutive series of patients from a single institution was retrospectively evaluated. Adverse events (AE) were assessed from patients' files and during follow-up examination. Current pain level was evaluated using the Visual Analogue Scale (VAS). The disability score of arm, shoulder and hand (DASH) as well as the Constant-Murley score were assessed. Patient satisfaction was evaluated by questionnaire. RESULTS: Forty-nine patients with a mean age of 72.0 ± 10.0 years were included with a follow-up of 2.2 years. Five patients showed twopart fractures (10%), 24 threepart fractures (50%) and 20 fourpart fractures (40%). Additional shaft fracture occurred in twelve cases (24%). Implant-related AE were recorded in six cases (12%). Pain under strain was moderate with a mean of 27.6 ± 27.1 mm. DASH score showed a mean of 25.9 ± 24.9. Constant score of the affected shoulder was 57 ± 23.8 with a mean difference of 16 points compared to reference shoulder. No significant differences in AE, VAS, DASH or Constant score could be found according to fracture groups. Most patients were satisfied with the surgical outcome (84%). CONCLUSIONS: The Targon PH+ nail demonstrated good functional results and low adverse events in geriatric patients. Additional studies including less experienced centres are required to further evaluate the possible benefits of this implant.

Titanium acetabular cementless cups combined with highly crosslinked polyethylene liner have very low rates of aseptic loosening.

BACKGROUND: There is a clear tendency towards cementless acetabular components in primary total hip arthroplasty. OBJECTIVE: The aim of this study was to assess the long-term clinical and radiological outcome of titanium cementless acetabular cups when combined with a highly crosslinked polyethylene liner. METHODS: This study is a retrospective follow-up of 67 cups in 64 patients. Clinical outcomes were assessed using the Harris Hip Score. Radiolucent lines, osteolysis and loosening were assessed radiologically. Implant survival was determined using the Kaplan-Meier analysis. RESULTS: The average Harris Hip Score at follow-up was 80.3 ± 14.5. Signs of osteolysis were observed in 7.1% of the radiographs. No aseptic loosening of the cup was reported. Survival of the cup with aseptic loosening as an endpoint was 100%. A comparison with 19 other studies using the same material combination demonstrated very similar results. All manufacturers with available studies have at least one report of 100% survivorship at 10-year follow-up for their titanium cup and highly crosslinked polyethylene acetabular component combination with aseptic loosening as an endpoint. CONCLUSIONS: The data suggests that the rate of aseptic loosening of a titanium cup combined with a highly-crosslinked polyethylene liner at 10-year follow-up could be as low as 0%.

Medial patellofemoral ligament reconstruction fails to correct mild patella alta in cases of patellofemoral instability-a case-control study.

PURPOSE: Medial patellofemoral ligament reconstruction (MPFL-R) is the gold standard in patella soft tissue surgery for patellofemoral instability. Although claimed, recent reports indicate that MPFL-R may fail to distalize the patella in mild cases of patella alta. The present study is a retrospective case-control study to compare radiographic patella height between MPFL-R and historical Insall's proximal realignment (IPR) pre- and post-operatively with respect to distalization and assess redislocation rates at a mid-term follow-up. METHODS: Sixty-four patients were age/sex matched (1:1), yielding 32 patients for group 1 MPFL-R (cases) and 32 patients for group 2 IPR (controls). Insall-Salvati, Blackburne-Peel and Caton-Deschamps indices were analyzed for differences pre- and post-operatively. An additional inter-rater reliability analysis was performed by means of intra-class correlation (ICC). Redislocation rates were considered as treatment failures in this study. RESULTS: ICC was excellent for all three patella indices. MPFL-R failed to show significant differences if compared to IPR with respect to distalization in mild stages of patella alta. Moreover, redislocation rates significantly favored MPFL-R (3.1%) over IPR (12.5%; p < 0.0001). CONCLUSIONS: MPFL-R has become a popular option to restore native patellofemoral biomechanics after ligament rupture. However, the procedure's potential to correct concomitant patella alta should not be overestimated and indications considered carefully.

Cartilage Surgery in Overweight Patients: Clinical and MRI Results after the Autologous Matrix-Induced Chondrogenesis Procedure.

Modern orthopaedic surgery provides a variety of techniques for cartilage repair. The Autologous Matrix-Induced Chondrogenesis (AMIC) procedure is a single-step technique with a collagen I/III scaffold for the treatment of full-thickness cartilage lesions. The aim of the study was to analyze the outcome of the AMIC procedure in overweight patients with knee cartilage defects. Overweight patients treated with AMIC surgery were followed up by clinical and MRI examination. 9 patients with a cartilage defect of the knee with a mean lesion size of 2.1 ± 1.2 cm2 and an average body mass index (BMI) of 29.3 were available for the follow-up. The Lysholm Score was significantly improved by the AMIC procedure (38 to 67, p ≤ 0.008). The VAS Score was significantly lower after the procedure (9 to 3, p ≤ 0.018). In the postoperative MOCART Scale, the scaffold reached defect covering of 80%. However, 2 patients had to be revised due to persisting knee pain. The AMIC procedure enhances pain reduction and gain of knee function for cartilage defects of overweight patients. However, in cases of an increased BMI, the patient had to be informed that success rate is reduced despite good defect covering.

Transfusions increase complications and infections after hip and knee arthroplasty: An analysis of 2760 cases.

BACKGROUND: Knee and hip replacement surgery are still the mainstay therapy for osteoarthritis. In spite of the improvement of techniques and implants, anemia is a relatively common complication, with transfusion rates of up to 23% in some centers. OBJECTIVE: The purpose of the study was to determine a correlation of transfusions to complications including infection since this topic is still being debated or even disputed in the literature. METHODS: This is a level III, single center retrospective observational cohort study of 2760 unilateral primary knee and hip replacements. Preoperative assessment, the number of transfusions and the occurrence of complications were collected and the correlations were analyzed using analysis of variance and logistic regression. RESULTS: Fifteen percent of all patients developed at least one complication. Transfusion rate was 9%. Risk factors for receiving a transfusion were female gender, hip replacement, American Society of Anesthesiologists' Score (ASA) > III, history of myocardial infarction, chronic cardiac disease, diabetes mellitus, chronic kidney disease, and length of surgery. The risk factors for developing a complication were: ASA score, presence of chronic renal insufficiency, and transfusion during hospital stay. Transfusion increases the risk of complications and infection rate. Complication rate with transfusion was 34.7% and without transfusion 13.2%. Infection rate without transfusion was 0.4% and with transfusion 2.82%. CONCLUSIONS: The complication rate is higher in transfused patients. The number of complications rises linearly with the number of transfusions. Infection rate is also higher after a transfusion. Efforts should be made to reduce the transfusion rate.

Computer-aided planning with exact implementation into surgical technique in TKA is as accurate as intraoperative navigation.

BACKGROUND: Exact positioning of implants and accuracy of alignment are important parameters to provide an long survivorship of endoprostheses after total knee arthroplasty. It was suggested that an alignment within 3∘ from centerline provides the best long-term survivorship of TKA. Therefore, computer-assisted navigation became more important in TKAs. Another tool to improve the accuracy in TKA is the preoperative planning software. OBJECTIVE: Main goal was to determine if advantages of an intraoperative navigation system during TKA can be reached by an exact implementation of a preoperative computer-aided planning. METHODS: Based on all patients (n= 100) underwent primarily TKA in 2015 and 2016 two groups were declared: (1) conventionally operated TKA without navigation system and (2) operation with an optical navigation system. Data on age, sex, date, operative time, severe complications and preoperative vs. postoperative alignment were collected retrospectively. RESULTS: The two groups do not differ in postoperative alignment and frequency of outliers. Furthermore, there was no difference referring to complications and the length of stay in hospital, but operative time was prolonged in the navigation-assisted group. CONCLUSIONS: It can be stated that conventional surgical techniques in TKA are as accurate as navigated ones if an exact preoperative computer aided planning is implemented during surgery.

Patient-specific instruments' routine use over conventional total knee arthroplasty remains inconclusive: Analysis of 961 cases.

BACKGROUND: An increasing demand for total knee arthroplasty (TKA) has pushed innovations in the industry and created a promising new technique called patient specific instruments (PSI). Early reports had promising results such as reducing operative time, cost, and improved alignment. More recent reports are conflicting. OBJECTIVE: We aimed to evaluate bleeding, operative time, complication rates, and in-hospital stay. METHODS: A monocentric retrospective analysis was performed on a total of 961 patients that met inclusion criteria. Four different TKA Systems, two of which were performed using conventional instrumentation (CI) (n= 768) and two with PSI (n= 193) were trialed under the same conditions by three senior surgeons. Operative time, complications, bleeding, range of motion, and length of stay were analyzed. RESULTS: There was no difference in operative time (p= 0.991) and length of hospital stay (p= 0.371) between PSI and CI approaches. Complication rates were lower in the PSI group. CI patients showed less non-compensated blood loss (p< 0.001) but required more transfusions (5.8% vs. 1.5%, p= 0.014). CONCLUSIONS: There was no difference in duration of surgery, length of stay, and total blood loss when performing TKA with PSI or CI. There were fewer complications in the PSI group. It remains debatable whether these findings justify routine use of PSI in TKA.

Deficits in subtalar pronation and supination proprioception in subjects with chronic ankle instability.

Deficits in joint position sense (JPS) and force sense (FS) are two functional insufficiencies contributing to chronic ankle instability (CAI). To date, JPS and FS have been only investigated in the sagittal and transverse movement planes but not in the functional movement plane of the pronators and supinators defined by the axis of the subtalar joint (STJ). The purpose of this study was to investigate subtalar JPS as well as pronator and supinator FS in supinated and pronated joint angle in subjects with CAI. Using a force transducer and a goniometer integrated in an apparatus with a movement axis corresponding to Inman's STJ axis, JPS and FS were examined in 20 sport students with CAI and 20 age- and sex-matched controls. Compared to uninjured subjects, CAI leads to reduced pronator (p<0.01) and supinator FS (p<0.01) as well as JPS (p<0.05). A significant main effect for 'angle' was found for JPS (P<0.0001). JPS is affected by a significant 'group'×'angle' interaction (p<0.05) indicating reduced JPS in the 24° supinated angle however not in the 8° pronated angle. The angle-specific JPS deficits indicate that the anatomical STJ axis has to be considered when assessing pronation and supination proprioception in subjects with CAI.

School sport-associated injuries in adolescents: A single center experience.

BACKGROUND: Each year, on average 1.26 million students face physical injuries at German schools and universities. Implementation of systematic prevention programs against school-associated injuries in adolescents is poor. Part of the reason might be a lack of data on nature and frequency of common school-associated injuries. OBJECTIVE: The aim of this study was to obtain qualitative and quantitative data that might help to develop prevention or protection strategies against sport-associated injuries at school. METHODS: A retrospective analysis was conducted on all patients between the ages of 10 and 16 years admitted from January 1st, 2009 to December 31st, 2013 to the emergency room of an academic teaching hospital for school-associated injuries (n= 901). For injuries associated with school sports, time of injury, type of sports and injured body region were analyzed. RESULTS: A significant part of school-associated injuries occurred in school sports (55.7%). The frequency of school sport-associated injuries per school day did not differ between months or seasons of the school year. Most injuries occurred between the ages of thirteen to fifteen. Ball sports were associated with 41% of all sport-associated injuries, particularly with soccer (22%). Distal extremities like hands (38.4%) and feet/ankle (30.3%) were predominantly injured, but only 5% of cases needed surgery. CONCLUSIONS: Most school-associated injuries occur in school sport, particularly with ball sports. Mostly, distal extremities were injured. Implementation of systematic prevention strategies for a reduction in finger injuries should be subject of future research.

The influence of different footprint preparation techniques on tissue regeneration in rotator cuff repair in an animal model.

INTRODUCTION: Rotator cuff tears are common diseases of the upper extremity. There are no recommendations to the surgeon on how to prepare the footprint to ensure optimal tendon-to-bone healing. However, biologic augmentation using stem cells and growth factors is considered to encourage the healing process of the tendon. The aim of the study was to investigate the biomechanical and histological outcome of different footprint preparations in rotator cuff repair. MATERIAL AND METHODS: One hundred and eighty-nine Sprague-Dawley rats were randomly assigned to either spongialization, radiofrequency ablation or an untreated control group. Rats were killed after 1 or 7 weeks for histological evaluation or after 7 weeks for biomechanical testing. RESULTS: Histological evaluation showed better tissue organization in the control and spongialization group compared to the radiofrequency ablation group. The highest collagen I to collagen III quotient was found in the control group, followed closely by the spongialization group. Measured quotients showed a decrease in the values after 1 week compared to the values after 7 weeks, except in the radiofrequency ablation group, where an increase was detected. A significant difference was found in the load to failure test comparing the radiofrequency ablation group to the spongialization group (p = 0.0409) and control group (p = 0.014), but not comparing the spongialization group to the control group (p = 0.2456). CONCLUSIONS: The results of this study suggest that spongialization of the footprint before attaching the torn supraspinatus tendon can lead to better structural properties and higher quality of tendon-to-bone restoration at the insertion area when compared with radiofrequency ablation.

Hip and knee effects after implantation of a drop foot stimulator.

BACKGROUND: An active ankle dorsiflexion is essential for a proper gait pattern. If there is a failure of the foot lifting, considerable impairments occur. The therapeutic effect of an implantable peroneus nerve stimulator (iPNS) for the ankle dorsiflexion is already approved by recent studies. However, possible affection for knee and hip motion after implantation of an iPNS is not well described. OBJECTIVE: The objective of this retrospective study was to examine with a patient cohort whether the use of iPNS induces a lower-extremity flexion withdrawal response in the form of an increased knee and hip flexion during swing phase. METHODS: Eighteen subjects (12 m/6 w) treated with an iPNS (ActiGait®, Otto Bock, Duderstadt, Germany) were examined in knee and hip motion by gait analysis with motion capture system (Vicon Motion System Ltd®, Oxford, UK) and Plug-in-Gait model after a mean follow up from 12.5 months. The data were evaluated and compared in activated and deactivated iPNS. RESULTS: Only little changes could be documented, as a slight average improvement in peak knee flexion during stand phase from 1.0° to 2.5° and peak hip flexion in stance from 3.1° to 2.1° In contrast, peak knee flexion during swing appeared similar (25.3° to 25.7°) same as peak hip flexion during swing. In comparison with the healthy extremity, a more symmetric course of the knee flexion during stand phase could be shown. CONCLUSIONS: No statistical significant improvements or changes in hip and knee joint could be shown in this study. Only a more symmetric knee flexion during stand phase and a less hip flexion during stand phase might be hints for a positive affection of iPNS for knee and hip joint. It seems that the positive effect of iPNS is only based on the improvement in ankle dorsiflexion according to the recent literature.

Deepening trochleoplasty combined with balanced medial patellofemoral ligament reconstruction for an adequate graft tensioning.

AIM: To evaluate our modified deepening trochleoplasty combined with a balanced medial patellofemoral ligament (MPFL) reconstruction for soft tissue alignement. METHODS: Thirty-three knees with with recurrent patellar dislocations and a trochlear dysplasia in 30 patients (m/f = 12/21, mean age 24 ± 9 years) underwent a combination of a modified deepening trochleoplasty and a balanced MPFL reconstruction for a medial soft tissue alignement. After a mean follow-up period of 29 ± 23 mo, patients' return to sports, possible complications as well as the clinical outcomes using the Kujala, International Knee Documentation Committee (IKDC) and Lysholm scoring were evaluated. Moreover, patients' satisfaction with the general outcome, the cosmetic outcome, the pre- and postoperative pain and a potential avoidance behaviour were assessed with additional standardized questionnaires which also included different visual analog scales. RESULTS: There were no signs of a persistent instability. The Kujala score improved from a mean of 64 ± 16 points to 94 ± 9 points, the Lysholm score improved from a mean of 63 ± 17 to 95 ± 6 points and the IKDC score from 58 ± 11 to 85 ± 12 points, P < 0.0001, respectively. The assessment of pain using a visual analog scale showed a significant pain reduction from a mean of 4.8 ± 2.0 to 1.3 ± 3.4 points (P < 0.0001). Two of 26 cases (92%) who were engaged in regular physical activity before surgery did not return to full sporting activities. One patient felt that his sport was too risky for his knee and reported an ongoing avoidance behaviour. The other patient preferred to wait for surgery of her contralateral knee. Of the eight patients who were not engaged in sporting activities before surgery, three started regular sporting activities after surgery. In 31 of the 33 cases (94%), the patients were very satisfied with the clinical outcome of the surgery. Regarding the cosmetic results, no patients felt impaired in their self-confidence and in their clothing decisions. CONCLUSION: Our technique shows a good clinical outcome in terms of the common scorings as well as in terms of pain, return to sports and patient satisfaction.

Testing the feasibility and safety of the Nintendo Wii gaming console in orthopedic rehabilitation: a pilot randomized controlled study.

INTRODUCTION: The Nintendo Wii game console is already used as an additional training device for e.g. neurological wards. Still there are limited data available regarding orthopedic rehabilitation. The authors' objective was to examine whether the Nintendo Wii is an appropriate and safe tool in rehabilitation after orthopedic knee surgery. MATERIAL AND METHODS: A prospective, randomized, controlled study comparing standard physiotherapy vs. standard physiotherapy plus game console training (Wii group) in patients having anterior cruciate ligament (ACL) repair or knee arthroplasty was conducted. The subjects of the Wii group (n = 17; mean age: 54 ±19 years) performed simple knee exercises daily under the supervision of a physiotherapist in addition to the normal rehabilitation program. The patients of the control group (n = 13; 52 ±18 years) were treated with physiotherapy only. The participants of both groups completed a questionnaire including the International Knee Documentation Committee (IKDC) score, the Modified Cincinnati Rating System and the Tegner Lysholm Knee Score prior to the operation, before discharge from hospital and four weeks after treatment. RESULTS: There was no significant difference in the score results between the Wii and the control group (p > 0.05). CONCLUSIONS: We demonstrated that physiotherapy using the Nintendo Wii gaming console after ACL reconstruction and knee arthroplasty does not negatively influence outcome. Because training with the Wii device was highly accepted by patients, we see an opportunity whereby additional training with a gaming console for a longer period of time could lead to even better results, regarding the training motivation and the outcome after orthopedic surgery.

Hip arthroscopy for excision of osteoid osteoma and for the application of a collagen cartilage implant: Case report in a professional athlete, and literature review.

BACKGROUND: Osteoid osteoma is an osteoblastic benign bone tumor usually affecting young adolescents. Intra-articular lesions are not common; usually the diagnosis is delayed. A lot of studies report difficulties and complications in the management of osteoid osteoma of the hip joint using imaging guided techniques or open surgical procedures. Only few published cases have described that it can be treated precisely using hip arthroscopy. Additionally, the use of hip arthroscopy to apply the Chondrofiller®, an acellular collagen matrix for the management of articular cartilage defects of the hip joint, has not yet been described. CASE PRESENTATION: This report presents an osteoid osteoma of the femoral neck. A 20-year-old female professional basketball player presented with pain in the left groin since more than 12 months. On magnetic resonance and computed tomography imaging, an osteoid osteoma was suggested. The lesion was successfully removed using arthroscopy. During surgery, a concomitant grade 4 cartilage lesion on the femoral head was detected. For the treatment of this severe defect we used the Chondrofiller®, which is a new acellular collagen implant for auto-regeneration of articular cartilage. This matrix was filled into the prepared and dried defect using CO2 arthroscopy. After the hardening of the matrix the surgery was finished. The patient was pain free shortly after the operation and returned to sports within 16 weeks. Return to high-performance sports 8 months after surgery was without of any sign of complaints. CONCLUSIONS: This article demonstrates that hip arthroscopy is a valuable tool for biopsy and excision of intra-articular osteoid osteoma affecting the hip joint, as well as for addressing other concomitant pathologies such as a severe synovitis or cartilage defects. CO2 arthroscopy provided good conditions for the drying and filling of the cartilage defect with the Chondrofiller®.

The angle-torque-relationship of the subtalar pronators and supinators in male athletes: A comparative study of soccer and handball players.

BACKGROUND: It is currently unclear how participation in different sports affects the angle-specific subtalar pronator and supinator muscle strength and pronator-to-supinator strength ratio (PSR). OBJECTIVE: Based on the hypothesis that both differences sport-related patterns of play and foot-ground interaction may lead to sport-specific muscle adaptations, this study compared the angle specific pronator and supinator strength capacity of handball and soccer players. METHODS: Eighteen healthy male handball and 19 soccer players performed maximum isometric voluntary isometric contractions using a custom-made testing apparatus. Peak pronator (PPT) and supinator torques (PST), pronator and supinator strength curves (normalised to the peak torque across all joint angles) and PSR were measured in five anatomical joint angles across the active subtalar range of motion (ROM). RESULTS: All analysed parameters were dependent on the subtalar joint angle. The ANOVA revealed significant `joint angle' × `group' interactions on PPT, pronator strength curves and PSR. No group differences were found for active subtalar ROM. CONCLUSION: In previously uninjured handball and soccer athletes, there were intrinsic differences in angle-specific subtalar pronator muscle strength. The lower PSR, which was found in the most supinated angle, can be seen as a risk factor for sustaining an ankle sprain.

Validation of a German version of the International Hip Outcome Tool (G-iHOT33) according to the COSMIN checklist: how much improvement is clinically relevant?

PURPOSE: The evaluation of the subjective health-related quality of life is especially for young, active patients with hip joint disorders important. The MAHORN study group has recently developed the "International Hip Outcome Tool" (iHOT33), a self-administered patient-reported outcome tool, which includes questions on the patient's symptoms, functional and sports limitations as well as social, emotional, and occupational limitations. The purpose of this study was to adapt and validate a German version of the iHOT33 according to the COSMIN checklist. METHODS: To validate the G-iHOT33, we conducted a prospective multicenter cohort study on patients with hip disorders and a score ≥4 on the modified Tegner Activity Scale. The patients completed the G-iHOT33 questionnaire twice at intervals of at least 2 weeks. In addition, we recorded the Hip Outcome Score (HOS), a modified Tegner Activity Scale (TAS), the EuroQol-5D (EQ5-D), and a subjective assessment of the limitations. Evaluation of psychometric properties was conducted following the COSMIN checklist for validation of health status measurement instruments. The methodical testing for reliability included internal consistency, test-retest reliability, and measurement error. For testing of validity, we analyzed construct validity, hypotheses testing, interpretability, and responsiveness. RESULTS: Between December 2013 and December 2014, eighty-three consecutive patients completed both questionnaires and were available for data analysis. Cronbach's α was 0.97 (95% CI 0.96, 0.99) confirming internal consistency and test-retest reliability of the G-iHOT-33 was high with an ICC = 0.88 (95% CI 0.80, 0.99). All a priori hypotheses were confirmed, further, no floor- or ceiling-effects occurred. The G-iHOT33 showed good responsiveness with a minimal important change (MIC) of 10 points. CONCLUSIONS: The German translation of the iHOT-33 (G-iHOT-33) is a viable tool for the evaluation of active patients with a hip disorder. Following the complete COSMIN checklist, we could prove that G-iHOT33 is a reliable, valid, and responsive PRO measurement tool. We could show that the minimal important change, a change of health condition the patient discerns is 10 points in the G-iHOT33 scale. This is the first study providing results on psychometric properties of the iHOT33 subscales. Level of evidence 1b validating cohort study.

Age dependent changes of the facet joint alignment for cervical disc replacement: A radiographic evaluation.

BACKGROUND: Artificial cervical disc implants are meant to last for several decades and therefore it is of interest, how the cervical facet joints undergo physiological changes over the course of years. OBJECTIVE: The primary purpose of this study is to investigate an age dependent deformation in human cervical facet joints. MATERIAL AND METHODS: The motion segments C2 to Th1 were measured in the cervical X-rays of 131 patients, aged between 14 and 88 years. The cranial and caudal facet joint angles were determined for each segment. The linear regression between the facet joint angle and age was determined. Furthermore the average as well as the standard deviation of the facet joint angle was determined for two groups, one group aged up to 57 years and the other group from 58 years upwards. The results were compared by means of the t-test. RESULTS: The angles of the cranial facet joint surfaces C3-C7 ranged from 54° to 64°, those of the caudal facet joint surfaces C3-C7 from 52° to 58°. The alignment of both, the cranial and the caudal facet joint surfaces flattened with increasing age. The group with the older patients had significant lower facet joint angles than the group with the younger patients. CONCLUSION: In conclusion, it should be taken into consideration, how the design of an artificial cervical disc needs to be adapted for a vertebral segment depending on the facet joint angle. Thus the articulation of a cervical motion segment can be optimized, so that it moves within a normal physiological manner.

Surgical complications following ESIN for clavicular mid-shaft fractures do not limit functional or patient-perceived outcome.

Elastic intramedullary nailing (ESIN) has been proposed as an alternative minimal-invasive method for the operative management of mid-shaft fractures of the clavicle. However, a relevant complication rate has been reported in previous cohorts. The present retrospective single-centre study aimed to analyse the complications following ESIN in adult patients with clavicular mid-shaft fractures (Allman type I) and their impact on functional and patient-perceived outcome measures. Results were compared to a control group receiving locking plate osteosynthesis. The clinical course and outcome of operatively managed patients with clavicular mid-shaft fractures were retrospectively analysed. Patients were assigned to group A (ESIN) and group B (plate fixation). Radiological, functional (Constant Murley Shoulder Outcome Score (CS), the Disabilities of the Arm, Shoulder and Hand (DASH) Score, the Oxford Shoulder Score (OSS)), and patient perceived aesthetic and clinical outcome were measured. A total of 47 (33 male, 14 female) operatively managed patients with a mean age of 26.7 ± 14.9 years and a follow up time of 38.1 ± 19.4 months were analysed. 36 patients were treated by ESIN (Group A), whereas 11 patients received open reduction and internal plate fixation (Group B). Patients were operatively treated with a mean delay of 7.4 ± 9.3 days (group A: 6.6 ± 8.7 days, group B: 10.2 ± 11.1 days, p=0.326) between trauma and the surgical index procedure. There were no significant differences in the functional (CS: p=0.338, DASH: p=0.247, OSS: p=0.434) and patient-perceived (p=0.346) outcome measures between both groups. Surgical complications were noted in 14 patients (group A: 12, group B: 2) and non-union in 4 patients (group A: 3, group B: 1). There was no correlation between the recorded complications as assessed by the Clavien and Dindo classification and the functional as well as the patient-perceived outcome measures. Despite a relevant incidence rate of surgical complications, ESIN provides good to excellent functional and patient-perceived results in the treatment of clavicular mid-shaft fractures.