Interobserver reliability of scapula fracture classifications in intra- and extra-articular injury patterns.

BACKGROUND: Morphology and glenoid involvement determine the necessity of surgical management in scapula fractures. While being present in only a small share of patients with shoulder trauma, numerous classification systems have been in use over the years for categorization of scapula fractures. The purpose of this study was to evaluate the established AO/OTA classification in comparison to the classification system of Euler and Rüedi (ER) with regard to interobserver reliability and confidence in clinical practice. METHODS: Based on CT imaging, 149 patients with scapula fractures were retrospectively categorized by two trauma surgeons and two radiologists using the classification systems of ER and AO/OTA. To measure the interrater reliability, Fleiss kappa (κ) was calculated independently for both fracture classifications. Rater confidence was stated subjectively on a five-point scale and compared with Wilcoxon signed rank tests. Additionally, we computed the intraclass correlation coefficient (ICC) based on absolute agreement in a two-way random effects model to assess the diagnostic confidence agreement between observers. RESULTS: In scapula fractures involving the glenoid fossa, interrater reliability was substantial (κ = 0.722; 95% confidence interval [CI] 0.676-0.769) for the AO/OTA classification in contrast to moderate agreement (κ = 0.579; 95% CI 0.525-0.634) for the ER classification system. Diagnostic confidence for intra-articular fracture patterns was superior using the AO/OTA classification compared to ER (p < 0.001) with higher confidence agreement (ICC: 0.882 versus 0.831). For extra-articular fractures, ER (κ = 0.817; 95% CI 0.771-0.863) provided better interrater reliability compared to AO/OTA (κ = 0.734; 95% CI 0.692-0.776) with higher diagnostic confidence (p < 0.001) and superior agreement between confidence ratings (ICC: 0.881 versus 0.912). CONCLUSIONS: The AO/OTA classification is most suitable to categorize intra-articular scapula fractures with glenoid involvement, whereas the classification system of Euler and Rüedi appears to be superior in extra-articular injury patterns with fractures involving only the scapula body, spine, acromion and coracoid process.

Indoor Bouldering-A Prospective Injury Evaluation.

INTRODUCTION: Bouldering has become a sport of growing interest, but little prospective evidence exists about injury proportions and patterns. The purpose of this study was to prospectively evaluate the cause of injuries sustained during indoor bouldering, proportion of affected body location, and injury severity. METHODS: Proportions and patterns of injury among German-speaking indoor boulderers were evaluated prospectively in an explorative cohort study. Participants completed a baseline questionnaire assessing anthropometric data and sport-specific potential preventive and risk factors, followed by monthly injury questionnaires including injury location and injury severity over a period of 12 mo. RESULTS: Out of 507 boulderers, 222 (44%) sustained 305 injuries. Of those, 78% (n=238) were classified as Union Internationale de Associations d'Alpinisme (UIAA) 1, 19% (n=57) as UIAA 2, and 3% (n=10) as UIAA 3. Injuries of the upper extremities accounted for 63% (n=191) of all injuries. Injuries of the lower extremities accounted for 23% (n=71) but were more often classified as UIAA≥2 (P=0.0071; odds ratio [OR] 2.23; 95% CI 1.23-4.04) and were more often caused by falling (P=0.0005; OR 2.92; 95% CI 1.57-5.42) and jumping off the wall (P<0.0001; OR 4.39; 95% CI 2.25-8.56) than injuries of other body locations. There was no statistically significant protective effect of the evaluated potential preventive measures. Participants who used heavily downturned climbing shoes had a higher risk of sustaining a UIAA ≥2 injury (P=0.0034; OR 2.58; 95% CI 1.34-4.95). CONCLUSIONS: Injuries in indoor bouldering are common. Lower extremity injuries are associated with higher injury severity. Preventive measures need to be established to reduce bouldering injuries, especially during falls and landings.

[Do COVID-19 restrictions lead to a decrease in severely injured patients at a level 1 trauma center in Germany?] / Führt eine COVID-19-bedingte Ausgangsbeschränkung zu einer Reduktion schwer verletzter Patienten an einem überregionalen Traumazentrum?

BACKGROUND: Intensive care and ventilator capacities are essential for treatment of COVID-19 patients. Severely injured patients are often in continuous need of intensive care and ventilator treatment. The question arises, whether restrictions related to COVID-19 have led to a decrease in severely injured patients and thus to an increase in intensive care unit (ICU) capacity. MATERIAL AND METHODS: A retrospective analysis of all seriously injured patients with an injury severity score (ISS) ≥16 was performed between 17 March and 30 April 2020 at a level 1 trauma center in Germany. The mechanism of injury and the ISS were recorded. Further data were collected as to whether it was a work-related accident, a documented suicide attempt and if surgery was necessary in the first 24 h after arrival in hospital. Data from 2018 and 2019 served as a control group. RESULTS: There was no substantial difference in the total number of seriously injured patients (2018 n = 30, 2019 n = 23, 2020 n = 27). Furthermore, there was no relevant difference in the number of patients needing intensive care or ventilator treatment when leaving the shock room. The number of patients needing an operative intervention within the first 24 h after arriving at hospital was slightly higher in 2020. The mean ISS was at a constant level during all 3 years. In 2020 there was no polytraumatized motorbike rider, who did not have a work-related accident (2018 n = 5, 2019 n = 4, 2020 n = 0). A noticeable increase in work-related accidents was observed (2018: 10%, 2019: 26.1%, 2020 44.4%). DISCUSSION: Restrictions related to COVID-19 did not lead to a reduction in seriously injured patients needing ICU care. Due to the monocentric data analysis there is room for misinterpretation. In general, intensive care and operating capacities should be managed with adequate consideration for seriously injured patients even in times of crisis, such as the COVID-19 pandemic. Confirmation through the German Trauma Register is pending.

[Smartphone-based photographic wound documentation improves the quality of medical accounting in orthopedic and plastic surgery]. / Qualitätssteigerung der Abrechnungsprüfung durch Smartphone-basierte Fotodokumentation in der Unfall­, Hand- und plastischen Chirurgie.

BACKGROUND: Photographic documentation of wounds, decubitus ulcers, tumors, open fractures and infections is an important part of digital patient files. It is unclear whether the photographic documentation has an effect on medical accounting with health insurance companies. OBJECTIVE: It was hypothesized that Smartphone-based systematic photographic documentation can improve the confirmation of proceeds-relevant diagnoses and procedures as well as the duration. MATERIAL AND METHODS: Staff in the emergency room, operating theater, outpatient clinic and on the wards were equipped with digital devices (Smartphone, tablet) including a photo-app. Medical accounting with the health insurance companies and identification of all case conferences in which the photographic documentation had effected a change in proceeds were analyzed for 2019 in a retrospective manner. RESULTS: Overall, 372 cases were discussed of which 27 cases were affected by the digital photographic documentation. Photographic documentation was used for clarification of the operative procedure (n = 5), primary diagnosis (n = 10), secondary diagnosis (n = 3), and length of hospitalization (n = 9). An average of 2119 € was negotiated and added per case affected by photographic documentation. Hereby, a level 1 trauma center gained an estimated 65,328 € in revenue. DISCUSSION: The use of Smartphone based photographic documentation can improve the overall quality of patient files and thus avoid loss of revenue. The implementation of digital devices with corresponding software is an important component of the digital structural change in hospitals.

[Local flaps as a last attempt to avoid lower extremity amputation: an overview]. / Lokale Lappenplastiken als letzter Versuch vor der Unterschenkelamputation: eine Übersicht.

BACKGROUND: Soft tissue reconstruction in aged patients is challenging. Free tissue transfer can be carried out in healthy patients with a high success rate despite old age. When free tissue transfer is contraindicated in multimorbid patients, local flaps are often chosen, which are associated with a high complication rate. Such salvage interventions must be selected so that an amputation is not disadvantageously influenced by the selection of the donor site or is even impossible. METHODS: The three distally based local flaps the sural artery flap, peroneus brevis muscle flap and perforator-based propeller flaps are discussed with respect to placement of the donor site as well as wound healing disorders. RESULTS: The sural artery flap is disadvantageous as the donor site because the proximal dorsal calf region is affected, which in the case of a below the knee amputation enables soft tissue covering of the stump. CONCLUSION: If a local flap is to be used as a salvage surgery in an attempt to prevent a below the knee amputation in a patient who is not suitable for free tissue transfer, special emphasis must be placed on the donor site of this flap. The proximal dorsal aspects of the distal calf are required for covering a potential stump and should not be violated by harvesting a local flap.

[Outcome after plate stabilization of symphyseal diastasis]. / Ergebnisse nach Plattenstabilisierung der Symphysensprengung.

BACKGROUND: Separation of the pubic symphysis with corresponding diastasis can be stabilized by symphyseal plating. OBJECTIVE: Which pelvic injuries are stabilized with symphyseal plating and what is their outcome? MATERIAL AND METHODS: A retrospective evaluation of 64 patients who underwent symphyseal plating over a period of 24 months was conducted. RESULTS: Of the patients 56 were male and 8 female with a mean age of 44 years (SD ± 17 years). The main cause of the pelvic injuries were traffic accidents. The distribution according to the AO fracture classification was 14â€¯× B1, 10â€¯× B2, 5â€¯× B3, 23â€¯× C1, 9â€¯× C2 and 3â€¯× C3 injuries. The distribution according to the Young and Burgess classification showed 9â€¯× APC I, 18â€¯× APC II, 13â€¯× APC III, 9â€¯× LC I, 3â€¯× LC II, 2â€¯× LC III and 10â€¯× VS injuries. The mean Injury Severity Score (ISS) was 32 (SD ± 17) and the mean inpatient stay was 29 days (SD ± 16 days; positive correlation p ≤ 0.001). Radiological implant loosening occurred in 52 patients. 14 patients required treatment for severe complications. The leading reason for revision surgery was implant failure (n = 8). CONCLUSION: These observations suggest that radiological signs of implant loosening are commonly observed but rarely the reason for revision surgery. Complete implant failures, however; occur mainly within the first postoperative weeks and require early revision. A timely clarification by additional X-ray imaging should be carried out if this is suspected.

Perioperative redistribution of regional ventilation and pulmonary function: a prospective observational study in two cohorts of patients at risk for postoperative pulmonary complications.

BACKGROUND: Postoperative pulmonary complications (PPCs) increase morbidity and mortality of surgical patients, duration of hospital stay and costs. Postoperative atelectasis of dorsal lung regions as a common PPC has been described before, but its clinical relevance is insufficiently examined. Pulmonary electrical impedance tomography (EIT) enables the bedside visualization of regional ventilation in real-time within a transversal section of the lung. Dorsal atelectasis or effusions might cause a ventral redistribution of ventilation. We hypothesized the existence of ventral redistribution in spontaneously breathing patients during their recovery from abdominal and peripheral surgery and that vital capacity is reduced if regional ventilation shifts to ventral lung regions. METHODS: This prospective observational study included 69 adult patients undergoing elective surgery with an expected intermediate or high risk for PPCs. Patients undergoing abdominal and peripheral surgery were recruited to obtain groups of equal size. Patients received general anesthesia with and without additional regional anesthesia. On the preoperative, the first and the third postoperative day, EIT was performed at rest and during spirometry (forced breathing). The center of ventilation in dorso-ventral direction (COVy) was calculated. RESULTS: Both groups received intraoperative low tidal volume ventilation. Postoperative ventral redistribution of ventilation (forced breathing COVy; preoperative: 16.5 (16.0-17.3); first day: 17.8 (16.9-18.2), p < 0.004; third day: 17.4 (16.2-18.2), p = 0.020) and decreased forced vital capacity in percentage of predicted values (FVC%predicted) (median: 93, 58, 64%, respectively) persisted after abdominal surgery. In addition, dorsal to ventral shift was associated with a decrease of the FVC%predicted on the third postoperative day (r = - 0.66; p < 0.001). A redistribution of pulmonary ventilation was not observed after peripheral surgery. FVC%predicted was only decreased on the first postoperative day (median FVC%predicted on the preoperative, first and third day: 85, 81 and 88%, respectively). In ten patients occurred pulmonary complications after abdominal surgery also in two patients after peripheral surgery. CONCLUSIONS: After abdominal surgery ventral redistribution of ventilation persisted up to the third postoperative day and was associated with decreased vital capacity. The peripheral surgery group showed only minor changes in vital capacity, suggesting a role of the location of surgery for postoperative redistribution of pulmonary ventilation. TRIAL REGISTRATION: This prospective observational single centre study was submitted to registration prior to patient enrollment at ClinicalTrials.gov (NCT02419196, Date of registration: December 1, 2014). Registration was finalized at April 17, 2015.

The Fascia-Only Reverse Posterior Interosseous Artery Flap.

PURPOSE: Fascia flaps are a preferred method to reconstruct the soft tissue envelope of the hand when a thin and pliable flap is required to cover exposed tendons. The aim of this study was to report on our experience with the fascia-only reversed posterior interosseous artery flap. Contrary to commonly used fascia flaps, this flap does not require free tissue transfer. METHODS: In this retrospective review, 5 patients were identified, each of whom underwent soft tissue reconstruction with a reversed posterior interosseous artery fascia flap. The operative technique is similar to the harvest of a fasciocutaneous flap except that only the fascia is harvested through a straight incision. RESULTS: No flap loss occurred. In 2 patients a distal wound dehiscence occurred, which healed by secondary intention. No venous congestion or iatrogenic lesion of the motor nerves to the extensor muscles was encountered. CONCLUSIONS: The fascia-only reverse posterior interosseous artery flap represents a locally available, pedicled option. With regard to the quality of the transferred tissue, this flap is comparable to the temporalis fascia flap. Major advantages are that the donor site is confined to the ipsilateral extremity and microsurgery is not required. Contrary to the fasciocutaneous version, no skin graft has to be applied to the donor site, which improves cosmesis. We consider this flap a worthwhile alternative to other fascia flaps. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Local Autograft and Strong Pulvertaft Fixation Technique for Reconstruction of a Rerupture of the Extensor Hallucis Longus Tendon: A Case Report.

There are different treatment options for extensor hallucis longus injuries. For primary repair, the end-to-end suture is recommended. The treatment of reruptures or tendon defects is challenging, and a wide range of procedures have been used in this regard, including primary and secondary repairs with and without auto- and allografts. To overcome the disadvantages of second-site morbidity and to achieve high primary stability, we demonstrate a technique using a local tendon graft in combination with a strong Pulvertaft suture technique in a case of rerupture of the extensor hallucis longus tendon.

The role of CT scan in postoperative evaluation of distal radius fractures: Retrospective analysis in regard to complications and revision rates.

BACKGROUND: Intraarticular fractures of the distal radius present a challenging problem for surgeons. While preoperative CT scans are considered helpful to understand the type of fracture and to choose an adequate approach, the role of postoperative CT scans is not yet clearly defined. The aim of this study was to analyze indications for postoperative CT scans and to evaluate its potential therapeutic consequence in regard to detection of complications and its influence on revision rates in intraarticular fractures. These findings were used to establish an algorithm to help identifying patients that benefit from a postoperative CT scan. PATIENTS AND METHODS: Ninety-two patients with intraarticular fractures were included. AO type C fractures were seen in about 90% of patients, with type C3 being present in 55% of the patients. According to Frykman's classification type 7 and 8 fractures were found in 93%. Data was analyzed in regard to radiographic results, complications and indication for a postoperative CT scan. RESULTS: Six patients underwent revision surgery. When analyzing data in regard to correlation of radiographs and CT Scans a statistically significant correlation was found. CONCLUSIONS: A high correlation between both imaging techniques can be shown. In inconclusive radiographs, CT scans are recommended to rule out intraarticular screw placement or step offs. Due to the number of patients and the retrospective design, further studies are needed.

Comparison of open reduction and internal fixation and primary total hip replacement for osteoporotic acetabular fractures: a retrospective clinical study.

PURPOSE: Treating acetabular fractures with open reduction and internal fixation (ORIF) may lead to poorer outcomes in older patients. As data for osteoporotic acetabular fractures are limited, we compared primary total hip replacement (THR) with ORIF for treating osteoporotic acetabular fractures, including those with posterior column instability. METHODS: All patients with osteoporotic acetabular fractures, treated with ORIF or primary THR from 2005 to 2015, were assessed retrospectively for clinical and radiologic outcomes. Indication criteria for selecting primary THR were evaluated. RESULTS: Twenty-three patients were treated with ORIF and nine with primary THR (performed with an anti-protrusion cage). If the posterior column was unstable, THR was combined with posterior column bridge plating. Indications for THR were the presence of a comminuted fracture pattern, approach-related risk factors for ORIF, and mobilization issues. Biomechanical reconstruction was acceptable with THR. Acetabular component loosening was observed only once. Secondary THR was indicated in 45 % of the ORIF cases. DISCUSSION: ORIF for acetabular fracture in older patients is unsatisfactory and may be even worse for osteoporotic fractures. Immobilization for long-term restricted weight bearing after ORIF is hazardous. Primary THR may enable early post-operative full weight-bearing. Various techniques, affording fixation of the unstable acetabular columns, are described. In THR with an anti-protrusion cage, only dorsal column instability needs to be addressed. CONCLUSION: The described technique achieved sufficient acetabular component stability. Primary THR with an anti-protrusion cage is an advantageous option to ORIF and should be strongly considered for osteoporotic acetabular fractures.

Comparing the MRI-based Goutallier Classification to an experimental quantitative MR spectroscopic fat measurement of the supraspinatus muscle.

BACKGROUND: The Goutallier Classification is a semi quantitative classification system to determine the amount of fatty degeneration in rotator cuff muscles. Although initially proposed for axial computer tomography scans it is currently applied to magnet-resonance-imaging-scans. The role for its clinical use is controversial, as the reliability of the classification has been shown to be inconsistent. The purpose of this study was to compare the semi quantitative MRI-based Goutallier Classification applied by 5 different raters to experimental MR spectroscopic quantitative fat measurement in order to determine the correlation between this classification system and the true extent of fatty degeneration shown by spectroscopy. METHODS: MRI-scans of 42 patients with rotator cuff tears were examined by 5 shoulder surgeons and were graduated according to the MRI-based Goutallier Classification proposed by Fuchs et al. Additionally the fat/water ratio was measured with MR spectroscopy using the experimental SPLASH technique. The semi quantitative grading according to the Goutallier Classification was statistically correlated with the quantitative measured fat/water ratio using Spearman's rank correlation. RESULTS: Statistical analysis of the data revealed only fair correlation of the Goutallier Classification system and the quantitative fat/water ratio with R = 0.35 (p < 0.05). By dichotomizing the scale the correlation was 0.72. The interobserver and intraobserver reliabilities were substantial with R = 0.62 and R = 0.74 (p < 0.01). CONCLUSION: The correlation between the semi quantitative MRI based Goutallier Classification system and MR spectroscopic fat measurement is weak. As an adequate estimation of fatty degeneration based on standard MRI may not be possible, quantitative methods need to be considered in order to increase diagnostic safety and thus provide patients with ideal care in regard to the amount of fatty degeneration. Spectroscopic MR measurement may increase the accuracy of the Goutallier classification and thus improve the prediction of clinical results after rotator cuff repair. However, these techniques are currently only available in an experimental setting.

Biomechanical analysis of different osteosyntheses and the combination with bone substitute in tibial head depression fractures.

BACKGROUND: Tibial head depression fractures demand a high level of fracture stabilization to prevent a secondary loss of reduction after surgery. Elderly individuals are at an increased risk of developing these fractures, and biomechanical investigations of the fractures are rare. Therefore, the aim of this study was to systematically analyze different types of osteosyntheses in combination with two commonly used bone substitutes. METHODS: Lateral tibial head depression fractures were created in synthetic bones. After reduction, the fractures were stabilized with eight different treatment options of osteosynthesis alone or in combination with a bone substitute. Two screws, 4 screws and a lateral buttress plate were investigated. As a bone substitute, two common clinically used calcium phosphate cements, Norian® Drillable and ChronOS™ Inject, were applied. Displacement of the articular fracture fragment (mm) during cyclic loading, stiffness (N/mm) and maximum load (N) in Load-to-Failure tests were measured. RESULTS: The three different osteosyntheses (Group 1: 2 screws, group 2: 4 screws, group 3: plate) alone revealed a significantly higher displacement compared to the control group (Group 7: ChronOS™ Inject only) (Group 1, 7 [p < 0.01]; group 2, 7 [p = 0.04]; group 3, 7 [p < 0.01]). However, the osteosyntheses in combination with bone substitute exhibited no differences in displacement compared to the control group. The buttress plate demonstrated a higher normalized maximum load than the 2 and 4 screw osteosynthesis. Comparing the two different bone substitutes to each other, ChronOS™ inject had a significantly higher stiffness and lower displacement than Norian® Drillable. CONCLUSIONS: The highest biomechanical stability under maximal loading was provided by a buttress plate osteosynthesis. A bone substitute, such as the biomechanically favorable ChronOS™ Inject, is essential to reduce the displacement under lower loading.

Biomechanical Analysis of the Modified Kessler, Lahey, Adelaide, and Becker Sutures for Flexor Tendon Repair.

PURPOSE: To compare the biomechanical properties of the modified Kessler, Lahey, Adelaide, and Becker repairs, which are marked by either a locking-loop or a cross-lock configuration. METHODS: Ninety-six lacerated porcine flexor tendons were repaired using the respective core suture and an epitendinous repair. Biomechanical testing was conducted under static and cyclic loads. Parameters of interest were 2-mm gap formation force, displacement during different loads, stiffness, maximum force, and mode of failure. RESULTS: The meaningful gap formation occurred in all 4 repairs at similar tension loads without any significant differences. Maximum force was highest in the Becker repair with a considerable difference compared with the modified Kessler and Lahey sutures. The Adelaide repair showed the highest stiffness. Overall, the displacement during cyclic loading demonstrated similar results with an exception between the Lahey and the Adelaide repairs at 10 N load. Failure by suture pull-out occurred in 42% in the modified Kessler, in 38% in the Lahey, and in 4% in the Adelaide repairs. The Becker repair failed only by suture rupture. CONCLUSIONS: The results of our study suggest that the difference between the 4-strand repairs with a cross-lock or a locking-loop configuration is minor in regard to gap formation. A strong epitendinous suture and the application of core suture pretension might prevent differences in gapping. However, the modified Kessler and Lahey repairs had an inferior maximum tensile strength and were prone to early failure caused by the narrow locking loops with their limited locking power. CLINICAL RELEVANCE: We suggest that surgeons should use pre-tension in repaired tendons to improve gap resistance and should avoid narrow locking loop anchoring to the tendon.

Biomechanical analysis of flexor tendon repair using knotted Kessler and Bunnell techniques and the knotless Bunnell technique.

PURPOSE: To evaluate a knotless Bunnell suture in flexor tendon repair. METHODS: Eighty porcine flexor digitorum tendons were assigned to 4 different suture techniques. Group 1 was repaired using a modified 4-strand knotted Kessler suture and served as a control group. Group 2 was repaired using a 4-strand knotted Bunnell suture. Group 3 used a 4-strand knotless Bunnell suture. Group 4 used a 4-strand knotless Bunnell and knotless peripheral suture. Under static and cyclic testing we studied mode of failure, 2-mm gap formation force, displacement, and maximum load. RESULTS: The 4-strand knotless Bunnell suture did not show a notable difference with regard to 2-mm gap formation force, displacement, or maximum load in comparison to the modified 4-strand knotted Kessler suture. Adding a knotless peripheral suture improved the repair by a significant reduction of gap formation and displacement and an increase in maximum load. The 4-strand knotted Bunnell showed the highest maximum load but also a considerable lower resistance to gap formation and major displacement. CONCLUSIONS: Flexor tendon repair using a 4-strand knotless Bunnell suture showed similar tensile strength to a modified 4-strand knotted Kessler suture. Adding a knotless peripheral suture further improved the repair. CLINICAL RELEVANCE: A complete knotless 4-strand Bunnell suture including a barbed core- and peripheral suture might be an option for flexor tendon reconstruction.

Biomechanical analysis of the efficacy of locking plates during cyclic loading in metacarpal fractures.

PURPOSE: To analyse the biomechanical characteristics of locking plates under cyclic loading compared to a nonlocking plate in a diaphyseal metacarpal fracture. METHODS: Oblique diaphyseal shaft fractures in porcine metacarpal bones were created in a biomechanical fracture model. An anatomical reduction and stabilization with a nonlocking and a comparable locking plate in mono- or bicortical screw fixation followed. Under cyclic loading, the displacement, and in subsequent load-to-failure tests, the maximum load and stiffness were measured. RESULTS: For the monocortical screw fixation of the locking plate, a similar displacement, maximum load, and stiffness could be demonstrated compared to the bicortical screw fixation of the nonlocking plate. CONCLUSIONS: Locking plates in monocortical configuration may function as a useful alternative to the currently common treatment with bicortical fixations. Thereby, irritation of the flexor tendons would be avoided without compromising the stability, thus enabling the necessary early functional rehabilitation.

Bone substitute first or screws first? A biomechanical comparison of two operative techniques for tibial-head depression fractures.

BACKGROUND: The aim of this study was to investigate a drillable and injectable bone substitute (calcium phosphate cement) and the operative technique enabled by the drillable option in a new biomechanical fracture model for tibial depression fractures in synthetic bones. MATERIALS AND METHODS: Lateral depression fractures of the tibial plateau (AO 41-B2, Schatzker III) were created in a biomechanical fracture model in three different synthetic bones (Sawbone 3401, Synbone 1110/1116). Reproducible fractures were generated employing Synbone 1110, which exhibited a comparable strength to human osteoporotic bones and was used for the further experiments. After reduction of the fractures, the stabilization was performed with two different operative techniques. In group 1, first an osteosynthesis with four screws was performed and then the metaphyseal defect was filled up with calcium phosphate cement (Norian drillable). In group 2, initially the filling up with Norian drillable was done enabling a complete filling of the defect, followed by placing of the screws. Displacement under cyclic loading with 250 N for 3,000 cycles, stiffness, and maximum load in load-to-failure tests were determined. RESULTS: A comparison of the two operative techniques of stabilization showed a distinctly lower displacement and higher stiffness for group 2 when the defect was filled up first. For the maximum load, no significant differences could be demonstrated. CONCLUSIONS: A complete filling of the defect by first applying the calcium phosphate cement significantly reduces the secondary loss of reduction of the depression fracture fragment under cyclic loading with a clinically relevant partial weight bearing. The beneficial effects of drillable calcium phosphate cement may also be transferable to defects other than tibial-head depression fractures.

A locking contoured plate for distal fibular fractures: mechanical evaluation in an osteoporotic bone model using screws of different length.

Osteoporotic bone with poor mechanical capacity provides limited stability after fixation of ankle fractures. Stabilization with an implant providing increased fixation strength in osteoporotic bone could reduce failure rates of fixation and allow a more functional treatment. The purpose of this study was to evaluate a locking contoured plate for fixation of distal fibular fractures in comparison with a conventional contoured plate in an osteoporotic bone model. Eighty cylinders of osteoporotic bone surrogates were fixed with the two plates. We performed torque-to-failure and cyclic testing experiments using screws of different length with a Zwick/Roell testing machine. The locking system showed higher torque-to-failure and maximum torque levels as compared with the conventional plate in torque-to-failure experiments and torsional cyclic testing. The locking contoured plate provides improved fixation strength in the osteoporotic bone model. The locking system may be appropriate for fixation of distal fibular fractures, especially in osteoporotic bone with poor mechanical capacity.

Is nail-plate docking worth the effort? A biomechanical analysis of docking a plate and a nail in peri-implant femur fractures.

Purpose: The ideal treatment of peri-implant femur fractures (PIFFs) remains unclear due to the thin clinical and biomechanical evidence concerning the most suitable form of osteosynthesis. The purpose of the present study was thus to determine the biomechanical stability that results from combining a cephalomedullary nail and a plate for proximal PIFFs, especially when the nail-plate docking technique is applied. Methods: Twenty four PIFFs were simulated in both 12 foam and 12 composite specimens and were stabilized via a combination of a cephalomedullary nail and a plate. The control group (n = 6) had a nail and a plate without a connection, while the intervention group (n = 6) had a screw that connected the plate with the interlocking screw hole of the nail, thereby creating a nail-plate docking system. The specimens were evaluated under axial and torsional loading using a material-testing machine and a 3D metrology system. Results: The data regarding stiffness, failure load, and failure displacement showed significantly higher stability for specimens without nail-plate docking. For docked specimens, a non-significant trend toward a higher resistance to torque was observed. Both techniques displayed no significant difference in fracture gap displacement or total displacement. Conclusion: The present study suggests that nail-plate docking of a cephalomedullary nail, and a plate significantly decreases the stiffness and stability of osteosynthesis under axial loading. However, there seems to be a tendency toward higher resistance to torque. Therefore, surgeons should consider this technique if higher torsional stability is necessary, and they should decide against it, if axial stability is preferred.

Do we need another screw? Sacroiliac screw fixation in open-book pelvic ring injuries (APC type II).

Purpose: To compare anterior plate fixation (SP fixation) both alone and in combination with an additional posterior sacroiliac screw (SP+SIS fixation) as a treatment for pelvic ring injuries with widening of the pubic symphysis and disruption to the anterior sacroiliac ligaments. Methods: To find studies with pelvic ring injuries (APC II; B2.3d) and SP or SP+SIS fixation, a systematic literature review was conducted by searching four databases. A protocol was published a priori at Open Science Framework (https://doi.org/10.17605/OSF.IO/3YHAV). Exclusion criteria included perineal injuries, chronic instability of the symphysis, complete sacroiliac separation, and pediatric patients (age <18 years). Primary outcomes of interest were defined as implant failure, health-related quality of life, and revision rate. Results: Altogether, 1861 studies were screened, and 40 studies qualified for full-text analysis. In total, 14 studies (two surveys, six biomechanical studies, and six retrospective clinical studies) were included. The surveys revealed that surgeons who had more recently begun practicing were more likely to use posterior fixation (SP+ISS). The biomechanical studies were heterogenous and did not yield a uniform pattern. In clinical studies, 117 patients (45%) received SP fixation, and 142 patients (55%) received SP+SIS fixation. Complications occurred in 31 SP patients (30%) and in five SP+SIS patients (3.5%). Conclusion: A high risk of bias was uncovered, and reporting was found to be incomplete. SP+SIS may have the potential to improve outcomes, but the evidence remains too inconclusive to draw reliable recommendations.