Implant-free iliac crest bone graft procedure shows anatomic remodelling without redislocation in recurrent anterior shoulder instability after short-term follow-up.

INTRODUCTION: With the help of a J-shaped bicortical iliac crest bone graft, the morphology of the glenoid can be augmented without having to use screws to achieve glenohumeral stability. The aim of this retrospective clinical study was to evaluate the clinical stability and function of the shoulder joint as well as the radiological remodelling process and arthropathic outcomes following the J-bone graft technique. MATERIALS AND METHODS: 34 patients with recurrent shoulder dislocations and bony glenoid defects were treated with the J-bone graft technique between 2010 and 2018 at our level-I trauma centre. 15 patients (18 shoulders) could be recruited for the study. Pain levels, ASES, UCLA, SST, DASH, Rowe and WOSI Scores were collected using questionnaires. In 13 patients (16 shoulders) the Constant Score, ROM, CT with 3D reconstruction of the glenoid to assess the graft remodelling and X-rays were performed additionally. RESULTS: None of the patients suffered subluxations or recurrent dislocations during the follow-up period. The overall complication rate was 11%. The evaluation using objective and subjective shoulder function scores yielded good-to-excellent results. Radiological assessment at follow-up showed a low rate of moderate-to-severe arthritis (12%) and a high rate of shoulders without any signs of arthritic degeneration (53%). The CT scans all revealed an almost complete restoration of the glenoid with none of the grafts being resorbed. A rise in the average glenoid circumference and glenoid area could be demonstrated between preoperative measurements (81.6 and 82.4%, respectively) and follow-up measurements (104 and 102.5%, respectively). CONCLUSION: The results of this study show a successful stabilisation of the shoulder joint and a low complication rate following the J-bone graft technique. Remodelling of the bone graft could be demonstrated, which in turn led to an almost perfect glenoid surface area of 100%.

Outcome of Surgical Treated Isolated Pronator Teres Syndromes-A Retrospective Cohort Study and Complete Review of the Literature.

PURPOSE: This study aims to elucidate the occurrence of postoperative carpal tunnel syndrome (CTS), the functional outcome of patients with primary pronator teres syndrome (PTS), and review complete literature regarding this topic. MATERIAL AND METHODS: A retrospective chart review was conducted in patients with PTS at a single center. In all patients, a numeric Visual Analog Scale (VAS) score, Pinch-Test, Jamar hand dynamometer test (JAMAR), and the Disabilities of the Arm Shoulder and Hand (DASH) score were analyzed preoperatively and at final follow-up to assess outcome. Additionally, a complete review of the literature was performed, including all data dealing with pronator teres syndrome. RESULTS: Ten female and two male patients were included with a mean age of 49 years. Significant improvement in DASH and numeric VAS was detected at latest postoperative follow-up. In three patients, clinical signs of CTS pathology were detected during the follow-up period. One patient needed to be treated surgically, and in the other two patients, a conservative management was possible. In one patient (8%), a PTS recurrence was detected. All patients presented satisfied at latest follow-up. CONCLUSION: In one-fourth of our patients, a CTS occurred during the follow-up period. Therefore, focusing on double-crush syndrome in unclear or mixed symptoms is necessary to avoid multiple operations. Furthermore, it seems that assessment with NCV is not enough for diagnosing PTS; therefore, further research is needed to clarify this problem.

Complication rate after operative treatment of three- and four-part fractures of the proximal humerus: locking plate osteosynthesis versus proximal humeral nail.

PURPOSE: There is still disagreement regarding the optimal surgical treatment of three- and four-part fractures of the proximal humerus. The aim of this monocentric, retrospective study was to compare the complication rate of internal fixation with a locking plate versus proximal humeral nailing after a one-year follow-up. METHODS: From 2005 to 2016, 292 patients suffered a fracture of the proximal humerus and were treated surgically at our level-I trauma center. According to the inclusion criteria, 50 patients were included in this study: 19 of these (11 three-part fractures and 8 four-part fractures) were treated with a proximal humeral nail (HN) and 31 (12 three-part fractures and 19 four-part fractures) with a locking plate (LP) osteosynthesis. Classification was performed according to the Hertel classification. At a 1-year follow-up, the complication rate of the two treatment methods was compared. RESULTS: Twenty patients (40%) suffered at least one complication. Of these, six patients (12%) were treated with a HN and 14 (28%) with a LP (p = 0.39). The most frequent complication was screw perforation (22%), followed by non-union (16%). Humeral head necrosis (10%) occurred only in the LP cohort. One wound infection occurred in a patient treated with a HN. Four-part fractures were treated more frequently with a LP. However, the difference was non-significant in this sample (p = 0.186). CONCLUSIONS: The results of our study provide some evidence that in terms of complication rate, both treatment options are comparable for internal fixation of three- and four-part fractures of the proximal humerus. The type of fracture seems to be decisive for the choice of implant.

Different storage times and their effect on the bending load to failure testing of murine bone tissue.

Cryopreservation is a well-established method for bone storage. However, the ideal timing of mechanical testing after sacrificing the experimental animals is still under discussion and of significant importance to the presentation of accurate results. Therefore, the aim of this study was to investigate and compare different cryopreservation durations to native murine bone and whether there was an influence on mechanical bone testing. For this study the tibias of 57 female C57BL/6 mice-18-weeks of age-were harvested and randomly allocated to one of four groups with varying storage times: (1) frozen at -80 °C for 3 months, (2) frozen at -80 °C for 6 months, (3) frozen at -80 °C for 12 months and (4) native group. The native group was immediately tested after harvesting. The comparison of the mean strength and load to failure rates demonstrated a significant difference between the storage groups compared to the native control (p = 0.007). However, there was no difference in the strength and the load to failure values of bones of all storage groups when compared against each other. Once cryopreservation at -80 °C is performed, no differences of mechanical bone properties are seen up to 12 months of storage. When actual in vivo data is of close interest, immediate testing should be considered and is preferred. If comparison of groups is required and long-time storage is necessary, cryopreservation seems to be an accurate method at present.

Author Correction: Effect of two (short-term) storage methods on load to failure testing of murine bone tissue.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Management and outcome of traumatic subdural hematoma in 47 infants and children from a single center.

BACKGROUND: Traumatic brain injury (TBI) is a frequent cause of mortality and acquired neurological impairment in children. It is hypothesized, that with the adequate treatment of SDH in children and adolescence, excellent clinical and functional outcomes can be achieved. The aim of this study was to present the severity and outcome of traumatic SDH in children and adolescence as well as to analyze differences between patients treated surgically and conservatively. METHODS: In this study 47 infants and children with a subdural hematoma (SDH) were treated between 1992 and 2010 at a single level-one trauma center. Data regarding accident, treatment and outcomes were collected retrospectively. To classify the outcomes the Glasgow outcome scale (GOS) scores at hospital discharge and at follow-up visits were used. Severity of SDH was classified according to the Rotterdam score. RESULTS: In total, 47 cases were treated (21 surgically, 26 conservatively), with 10 patients needing delayed surgery. Overall, 89% of the patients were able to leave hospital, 5 patients died, 2 patients (5%) within 24 h, another 2 (5%) after 48 h and 1 (2%) within 7 days. In 25 patients (53%) a good recovery was recorded at the last follow-up visit. Outcome was mainly influenced by the following factors: age, severity of TBI, and neurological status. Overall, in 70% good clinical and neurological outcomes could be achieved. CONCLUSION: The results of this study confirmed that pediatric SDH is a rare, but serious condition. Despite a poor prognosis, most patients could be treated with good outcomes, given that the choice of treatment is correct. TRIAL REGISTRATION: Research registry 2686.

Minimally Invasive AC Joint Reconstruction System (MINAR®) in Modified Triple-Button Technique for the Treatment of Acute AC Joint Dislocation.

Acute acromioclavicular (AC) joint dislocation is a frequent sports injury with more than 100 different operation methods described. A total of 65 patients with an acute AC joint dislocation were treated with the modified MINAR® system between 2009 and 2013. Clinical outcome, horizontal and vertical instability, as well as concomitant intraarticular injuries were assessed. We used Zanca, stress and axial X-rays for radiological assessment. A Constant score of 95 (±8.8), University of California Los Angeles Shoulder score (UCLA) of 31 (±4.9), Disabilities of Arm, Shoulder and Hand (DASH) of 9.1 (±14.3), and Visual Analogue Scale (VAS) of 0.9 (±0.126) was found. A total of 30 patients (59%) had no signs of reduction loss, nine patients (18%) a slight loss, 11 patients (22%) a partial loss, and one patient (2%) a total loss. No significant influence on the clinical scores could be shown. The postoperative coracoclavicular (CC) distance negatively affected the Constant (p = 0.007) and UCLA scores (p = 0.035). A longer time interval to surgery had a negative influence on all scores (p ≤ 0.001). We could not find any signs of persistent horizontal instability or intraarticular injuries at follow-up. The MINAR® system promises satisfactory functional and radiological results. When setting the correct indication, patients benefit from an early operation. No persisting horizontal instability was observed following suturing of the AC capsule and the delta fascia.

Effect of two (short-term) storage methods on load to failure testing of murine bone tissue.

Since mechanical testing of bone quality is often delayed following euthanasia, the method of bone storage is of high importance in animal studies. Different storage methods may cause a change in the properties of bone tissue during mechanical testing. Therefore, the aim of this study was to investigate the biomechanical effects of two different fixation methods for bone tissue. We hypothesized that there is a difference between the load to failure values between the two groups. The tibias of fifteen 18-week-old female C57BL/6 mice were harvested and randomly allocated to three different groups with varying storage methods: (1) frozen at -80 °C, (2) paraformaldehyde working solution, and (3) native group. A storage time of two weeks prior to testing was chosen for groups 1 and 2. In group 3, referred to as the "native group", bones were immediately tested after the harvesting procedure. The comparison of the mean load to failure of all 3 groups (group 1: 28.7 N ± 6.1 N, group 2: 23.8 N ± 3.8 N and group 3: 23.7 N ± 5.7 N) did not reveal a significant difference. There was also no difference in strength or stiffness. The findings of the present study demonstrate that the two most common storage methods, do not have an influence on the biomechanical properties of murine bone over a two week period.

The buried knot technique for all inside graft link preparation leads to superior biomechanical graft link stability.

The aim of this study was to measure and compare the biomechanical properties of two different graft link preparation techniques for anterior cruciate ligament reconstruction. We hypothesised that there would be differences in elongation, load at failure and failure mode due to the different graft link preparation techniques. Thirty fresh-frozen anatomical specimen knees were used. Both tendons (semitendinosus and gracilis) were harvested and randomly assigned to two groups. Graft links prepared with a continuous loop technique were allocated to group 1, whereas those prepared with a buried-knot technique were allocated to group 2. The mechanical properties of both techniques were measured. A mean load to failure of 731 N and an overall graft elongation of 6 mm was found in the continuous loop group. In the buried-knot group, a higher load to failure (848 N) and a lower mean overall elongation (5 mm) was found. The buried-knot technique showed better results with significantly higher load to failure and significantly less elongation compared to the continuous loop technique. It is essential in clinical practice to choose the most accurate technique for graft link preparation to ensure graft stability, especially in the early phase of recovery.

A bigger suture diameter for anterior cruciate ligament all-inside graft link preparation leads to better graft stability: An anatomical specimen study.

BACKGROUND: In anterior cruciate ligament reconstruction, different suture types are used for graft link preparation. Thus the aim of this study was to determine whether differences in the diameter of the suture used influence biomechanical stability of the prepared graft. We hypothesized that the use of a greater suture diameter leads to a higher load to failure rate in tested graft links. METHODS: In an anatomic specimen study, ligament preparation was enrolled in 15 cadaveric knees. The material used was the semitendinosus/gracilis tendon, which was fresh frozen (-80°) after harvesting for four weeks. The grafts were then defrosted, randomized into two groups and prepared with the same technique: 12 with a suture; FiberWire No. 2 and 12 with a FiberWire No. 0. RESULTS: Overall, the group using FiberWire No. 2 presented with a mean load to failure rate of 730.67N, mean overall final elongation of the graft was 5.98mm. In the FiberWire No. 0 group mean load to failure was with a mean overall elongation of the graft of 6.96mm. Significant differences (P=0.006) between the two groups with regard to the load to failure rate were found, with FiberWire No. 2 withstanding forces better. There was no difference in elongation of the grafts or mode to failure between the two groups. CONCLUSIONS: Graft preparation with a bigger suture type is recommended to gain better load to failure rates, also in smaller-diameter grafts. Regarding the elongation rate, different suture types did not influence the outcome. LEVEL OF EVIDENCE: Anatomical specimen study, Level III.

Acromioclavicular joint dislocation treated with Bosworth screw and additional K-wiring: results after 7.8 years - still an adequate procedure?

BACKGROUND: The acromioclavicular (AC) joint dislocation is a major reason for shoulder instability. Different concepts of treatment and surgical methods are described in the literature. Thus, the purpose of this study was to present our data of long-term follow-up of patients having undergone treatment of acromioclavicular (AC) joint dislocation using the Bosworth Screw with additional K-wiring. METHODS: This study was conducted as a retrospective single centre data analysis. All patients treated operatively for AC joint dislocation with a Bosworth screw and additional K-wire fixation at our Department were asked to participate in this study. RESULTS: The study population consisted of 22 patients, 20 male and 2 female, with a mean age of 40 years ±15.6 years. Three grade-II lesions, 13 grade-III lesions, four grade-IV lesions and two grade-V lesions according to the Rockwood classification were found. The overall mean clinical outcome at the latest follow up was: Constant 95, DASH 6.4, ASES 94.6, SST 99.02, UCLA 33.1, ACJI 91.82 and VAS 0.29 - representing a good-to-excellent long-term outcome in all patients after at least 2 years follow-up (range; 2 - 19 years). Overall, 19 patients (86%) reported to be very satisfied with the achieved result, 15 patients (68%) reported to be able to participate in every sports activity and 16 patients (73%) reported to be able to perform their daily work without limitations. Overall, complications occurred in three patients (14%). Only one patient remained unsatisfied with the achieved result. CONCLUSION: Summarizing, our reported results showed that surgical fixation of acute AC joint dislocation with a Bosworth screw and additional K-wire fixation leads to good-to-excellent functional outcome and highly satisfactory results in the majority of patients. Despite its complications, in accordance with our results, Bosworth screw fixation with additional K-wiring in AC joint dislocation represents an adequate surgical procedure. LEVEL OF EVIDENCE: Level IV, retrospective study.