Hoffa fractures are associated with concomitant soft tissue injures and a high postoperative complication rate.

INTRODUCTION: Hoffa fractures are a rare and often overlooked entity. The main goal of surgical treatment is to restore the articular surface and maintain knee function. However, current clinical data indicate heterogeneous outcomes. The aim of this multicenter study was to obtain a representative data set of patients with isolated Hoffa fractures with special emphasis on concomitant soft tissue injuries, diagnostic algorithms, treatment strategies and functional outcomes. MATERIALS AND METHODS: Participating Level I trauma centres were asked to review their internal database for isolated Hoffa fractures treated surgically between 2010 and 2020. Demographics, mechanism of injury, diagnostic and therapeutic algorithm, Letenneur classification, concomitant soft tissue injuries, and postoperative knee function and complications were analysed. RESULTS: A total of 56 patients from six participating trauma centres were included. The median age at injury was 45 years (15-94) with a median follow-up of 19 months (2-108). The most common mechanism of injury was high-energy trauma, with unicondylar lateral Letenneur type I and II fractures being the most common. Surgical treatment was independent of the type of fracture and included isolated screw fixation, combined plate and screw fixation and isolated plate osteosynthesis. Isolated screw fixation resulted in significantly better range of motion (ROM) values (p = 0.032), but the highest number of postoperative complications (n = 14/20, n.s.) compared to the other fixation techniques. The highest number of fixation failures requiring revision was observed in the plate and screw fixation group (n = 3/8, p = 0.008). Osteochondral flake fractures (n = 12/43, 27%) and lateral meniscus injuries (n = 5/49, 10%) were commonly seen in Hoffa fractures. CONCLUSIONS: Treatment of Hoffa fractures with screw fixation resulted in significantly better functional outcomes, probably due to less comminuted fractures. Concomitant cartilage, meniscal and ligamentous injuries are common and warrant preoperative recognition and management.

A lateral fracture step-off of 2mm increases intra-articular pressure following tibial plateau fracture.

INTRODUCTION: The aim of this study was to evaluate the effects of increasing posttraumatic step-offs after lateral tibial plateau fracture reduction on the intra-articular pressure. MATERIALS AND METHODS: In eight fresh-frozen human cadaveric knees with intact menisci, a standardized sagittal osteotomy of the lateral tibial condyle was performed as an OTA/AO type 41-B1 fracture-model. The fragment was fixed by a customized sled including an angular stable tibia plate to evaluate step-offs from 0 mm to 8 mm in 1mm increments. In a servo-hydraulic testing machine, an axial force was applied to the tibial plateau in 0° (700N), 15° (700N), 30° (700N), 60° (350N), and 90 ° (350N) of flexion while the joint pressure was recorded by two pressure sensors. RESULTS: A 1mm step-off did not result in an increased joint pressure. At 60° of flexion a 2mm step-off increased the lateral joint pressure by 61.84kPa (P = 0.0027). In 30° of flexion, a 3mm step raised the lateral joint pressure by 66.80kPa (p = 0.0017), whereas in 0°, 15° and 90° of flexion, a 4mm step increased the pressure by >50kPa (P < 0.05). Concomitant medial joint pressure increments were lower than those in the lateral plateau. A significant increase of 19-24kPa in the medial joint pressure was detected in 90° of flexion with a 1mm lateral step (P = 0.0075), in 15° and 60° of flexion with a 2mm step (P < 0.05), in 0° of flexion with a 4mm step (P = 0.0215) and in 30° of flexion with a 7mm step (P = 0.0487). CONCLUSION: Lateral fracture step-offs of 2mm or larger should be reduced intraoperatively to avoid large increases in lateral joint pressure.

Primary stability of single-stage revision reconstruction of the anterior cruciate ligament in case of failure of dynamic intraligamentary stabilization depends on implant position during ACL repair.

INTRODUCTION: The object of this study was to evaluate the primary stability of tibial interference screw (IFS) fixation in single-stage revision surgery of the anterior cruciate ligament (ACL) in the case of recurrent instability after ACL repair with dynamic intraligamentary stabilization (DIS), dependent on the implant position during DIS. MATERIALS AND METHODS: Tibial aperture fixation in ACL reconstruction (ACL-R) was performed in a porcine knee model using an IFS. Native ACL-R was performed in the control group (n = 15). In the intervention groups DIS and subsequent implant removal were performed prior to single-stage revision ACL-R. A distance of 20 mm in group R-DIS1 (n = 15) and 5 mm in group R-DIS2 (n = 15) was left between the joint line and the implant during DIS. Specimens were mounted in a material-testing machine and load-to-failure was applied in a worst-case-scenario. RESULTS: Load to failure was 454 ± 111 N in the R-DIS1 group, 154 ± 71 N in the R-DIS2 group and 405 ± 105 N in the primary ACL-R group. Load-to-failure, stiffness and elongation of the group R-DIS2 were significantly inferior in comparison to R-DIS1 and ACL-R respectively (p < 0.001). No significant difference was found between load-to-failure, stiffness and elongation of R-DIS1 and the control group. CONCLUSION: Primary stability of tibial aperture fixation in single-stage revision ACL-R in case of recurrent instability after DIS depends on monobloc position during ACL repair. Primary stability is comparable to aperture fixation in primary ACL-R, if a bone stock of 20 mm is left between the monobloc and the tibial joint line during the initial procedure.

Sensitive and practical screening instrument for malnutrition in patients with chronic kidney disease.

OBJECTIVES: The aims of this study were to examine the diagnostic accuracy of the Malnutrition Universal Screening Tool (MUST) and the Patient-Generated Subjective Global Assessment Short Form (PG-SGA-SF) for detecting malnutrition in chronic kidney disease (CKD), study individual contributions of MUST and PG-SGA screening items to the explained variance in nutritional status (NS), and examine whether the PG-SGA-SF score, in combination with one of the items of the clinician's part of the cPG-SGA, can be used as a valid and compact nutrition assessment tool in patients with CKD. METHODS: This was a cross-sectional observational study with 123 patients with CKD who were screened for malnutrition risk by MUST and PG-SGA-SF. NS was determined by complete PG-SGA. Overall accuracy was calculated by the receiver operating curve area under the curve (ROC-AUC). Explained variance of individual screening items was assessed by Nagelkerke's R2, total explained variance was assessed by the increase of R2 after addition of items in manual stepwise forward selection. RESULTS: Of the patients, 44% were malnourished, which was detected by MUST in 24% and by PG-SGA-SF in 78%. Items "body mass index (BMI)" and "no food intake" of the MUST together explained only 3.7% of the variance in NS, whereas the item "nutrition impact symptoms" (NIS) of the PG-SGA-SF explained 57%. Total explained variance in NS by MUST and PG-SGA-SF were 15% and 74%, respectively. The PG-SGA-SF combined with the "metabolic stress" item explained most (87%) and had a sensitivity of 94% to detect malnutrition. CONCLUSIONS: Most malnourished patients with CKD failed to be identified with the MUST, whereas the PG-SGA-SF detected the majority of them with the screening item "NIS" having the highest individual contribution to the explained variance in NS. Combination of PG-SGA-SF with the item "metabolic stress" had the highest overall accuracy to detect malnutrition.

[Ligament reconstruction in extensor tendon dislocation]. / Bandplastik bei Strecksehnenluxation über dem Fingergrundgelenk.

OBJECTIVE: Stabile recentering the extensor tendon over the top of the head of the metacarpal to restore the exact tension and the direction. INDICATIONS: Dislocation of the extensor tendon at the metacarpophalangeal (MP) joint with functional disabilities of the fingers. CONTRAINDICATIONS: Severe osteoarthritis of the MP joint. Accompanying injuries of collateral ligaments. Fibrosis of the MP joint or contractures of the intrinsic muscles. SURGICAL TECHNIQUE: Curved 8 cm skin incision at distal metacarpal, MP joint, and proximal phalanx. A distally pedicled central tendon strip from the extensor digitorum communis (EDC) tendon is removed. Centralization of the tendon by reconstructing the sagittal ligament and the proximal part of the extensor hood. The tendon strip is wrapped around the tendon of the interossous muscle. POSTOPERATIVE MANAGEMENT: Immobilization of the MP joint in 30° flexion with free proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints for 4 weeks. Full fist after 5 weeks. RESULTS: In all 16 patients good or very good results were achieved. There were no recurrences of tendon dislocations, no MP joint contractures, and only a few minor extensor tendon adhesions.

[Suture techniques for flexor tendons of the hand]. / Nahttechniken für Beugesehnen der Hand.

BACKGROUND: The success of the flexor tendon suture depends on many factors. An important factor is that the tendon suture technique that must be carried out for flexor tendons is considerably more complex and more precise than for all other tendons of the body. OBJECTIVES: To discover important technical points that need to be considered during flexor tendon suturing. METHOD: We compiled the most important technical details in flexor tendon suturing from the literature and from personal experience. RESULTS: Details on core suture, peripheral suture, the tensile strength, gapping, the circulation of sutured tendons, gliding resistance and excisions are discussed. CONCLUSIONS: Flexor tendon suturing must be performed taking great care to conserve tissue.

The Müller acetabular reinforcement ring--still an option in acetabular revision of Paprosky 2 defects? Longterm results after 10 years.

BACKGROUND: Aim of this study was to measure the clinical and radiological longterm outcome after acetabular revision arthroplasty (RTHA) using the Müller acetabular reinforcement ring. MATERIAL AND METHODS: 86 patients with 90 revision arthroplasties and a mean age of 68 years (41 to 84) were included. The mean follow-up was 10 years (range 7-12). The Harris Hip Score and the WOMAC Index were used to assess pain and functional outcome. Furthermore clinical examination of range of motion and radiologic examinations were performed in 34 patients. RESULTS: The radiologic analysis reports no signs of loosening in 79%, 15% showed possibly loosening and 6% probable loosening. Definite radiologic loosening has not been detected. In the meantime 12 patients (13.3%) of 90 revision total hip arthroplasty underwent a revision of the acetabulum with change of the acetabular component which means a survival rate of 86.7% after 10 years follow-up. The mean center of rotation of the hip moved 0.15 cm (SD 0.74 cm) laterally and 0.1 cm (SD 0.97 cm) cranially based on the geometrically reconstructed center of rotation. A mean score of 58 points for the Harris Hip Score (range 14-93) indicated a poor functional outcome, while a mean value of 96 points (range 0-223) for the WOMAC Index indicated good results for functional outcome in daily living. CONCLUSIONS: The revision arthroplasty in cases with acetabular defects using the Müller acetabular reinforcement ring shows acceptable longterm results. LEVEL OF EVIDENCE: Level IV.

[Dynamic intraligamentary stabilization of the anterior cruciate ligament. Operative technique and short-term clinical results]. / Dynamische intraligamentäre Stabilisierung des vorderen Kreuzbandes. Operationstechnik und klinische Kurzzeitergebnisse.

BACKGROUND: Reconstruction of tears in the anterior cruciate ligament with a tendon graft is the current gold standard. OBJECTIVES: Dynamic intraligamentary stabilization is a new technique for preservation of the anterior cruciate ligament. METHODS: This article describes the indications, operative technique, rehabilitation and preliminary results after dynamic intraligamentary stabilization for acute anterior cruciate ligament ruptures. RESULTS: A total of 24 women and 31 men with an acute anterior cruciate ligament tear were included in a prospective clinical trial. Of the patients 26 had already been followed-up for 12 months and satisfying values for the Lysholm, Tegner and International Knee Documentation Committee (IKDC) outcome scores were achieved. High subjective patient satisfaction was also achieved. The Lachman test showed a mean anterior translation difference to the healthy side of 1.7 mm. CONCLUSION: Dynamic intraligamentary stabilization in combination with microfracturing of the notch can provide biomechanical and biological conditions for self-healing of the anterior cruciate ligament. Further clinical and biomechanical research is needed to identify appropriate patients and rupture types suitable for this new technique.

Comparing the outcomes between Chopart, Lisfranc and multiple metatarsal shaft fractures.

OBJECTIVES: Complex midfoot injuries could lead to severe functional impairment of mobility and quality of daily living. Aim of this study was to compare the clinical and functional outcomes of Chopart, Lisfranc fractures and multiple metatarsal shaft fractures. DESIGN: Retrospective case series. SETTING: Level one trauma center. INTERVENTION: Open or closed reduction and internal fixation with screws, K-wires, plates, external fixation or combination of different technics. MAIN OUTCOME MEASUREMENTS: The American Orthopaedic Foot and Ankle Society (AOFAS) Midfoot Score and the Maryland Foot Score were used to assess pain and functional outcome. 3D gait analysis, pedobarographic analysis and radiologic examinations were performed. The activity level was measured by a step counting accelerometer. All results were compared to an age-matched healthy control group. RESULTS: 24 patients with a median age of 44 years (16-72) were included: 12 patients with multiple metatarsal shaft fractures, 6 patients with Chopart and 6 patients with Lisfranc fractures. The median follow-up was 2.6 years. The pedobarographic analysis reports reduced contact time of the total foot (p = 0.08), the forefoot (p = 0.008) and the hallux (p = 0.015) for the injured foot. A median score of 64 for the SF-36, 64 for the AOFAS Midfoot Score and 73 for the Maryland Foot Score indicated a poor restoration of foot function. Multiple metatarsal shaft fractures presented a significantly lower walking speed (p = 0.03) and cadence (p = 0.04). CONCLUSION: The worst results were reported for multiple metatarsal shaft fractures on outcome scores, pedobarography, gait analysis and activity. Metatarsal serial fractures should not be underestimated as well as Chopart and Lisfranc fractures. LEVEL OF EVIDENCE: Level IV.

Comparison of outside-in and inside-out technique for tibial fixation of a soft-tissue graft in ACL reconstruction using the Shim technique.

INTRODUCTION: The aim of this study was to compare the biomechanical properties of tibial fixation of a free tendon graft in ACL reconstruction using the Shim, a new wedge-shaped implant, in an outside-in technique to fixation by the Shim used in an inside-out technique and fixation by interference screw in a porcine model. MATERIALS AND METHODS: Porcine tibia and flexor tendons were used. In Group 1, the Shim was applied outside-in. In Group 2, the Shim was inserted inside-out. In the Group 3, an 8-mm interference screw was used. Ten specimens were tested in each group. Load-to-failure, elongation, stiffness and failure mode were recorded. Cyclic loading was performed between 5 and 250 N for 1,000 cycles, followed by a load to failure testing. RESULTS: Mean maximum load-to-failure was 629.53 N in Group 1,648.54 N in Group 2 and 749.53 N in Group 3. There was no significant difference between the groups. Stiffness varied between 127.34 N/mm in Group 1, 151.27 N/mm in Group 2 and 182.25 N/mm in Group 3. No significant differences were found between outside-in Shim and interference screw fixation. No significant difference was found for elongation among the three groups. The main failure mode was a rupture of the tendon in the IFS group and a slippage of either the implant or the tendon in both groups using the Shim. CONCLUSIONS: As no statistically significant difference could be seen concerning load to failure, stiffness and elongation between the inside-out and the outside-in techniques, the Shim can be used for tibial fixation in an outside-in or inside-out technique depending on the preference of the surgeon. To prevent slippage of the graft a hybrid fixation should be considered.

[Treatment of periprosthetic fractures : new concepts in operative treatment]. / Versorgung periprothetischer Frakturen : Neue Konzepte in der operativen Therapie.

BACKGROUND: Periprosthetic fractures represent a common and complex challenge in the clinical practice in orthopedics and trauma surgery. Due to demographic changes characterized by increased life expectancy and higher numbers of primary arthroplasties, the number of periprosthetic fractures is increasing as well. Factors such as osteoporosis, multimorbidity and a highly active aging population additionally increase the complexity of periprosthetic fractures. INJURY PATTERNS: Most periprosthetic fractures affect the proximal and distal femur; however, periprosthetic fractures of the tibial head, the ankle, shoulders and the upper extremities as well as complex interprosthetic fractures pose an increasing challenge for orthopedic and trauma surgeons. THERAPY: Many therapeutic options exist and the number of implants especially designed to treat periprosthetic fractures is steadily rising. Principally, loosened prostheses are indicative for replacement operations whereas for periprosthetic fractures of well-anchored prostheses as a rule osteosynthesis is necessary. A standardized treatment algorithm does not yet exist and usually the decision of how to treat these fractures has to be made on an individual basis. PERSPECTIVES: The present article demonstrates the current state of open reduction and internal fixation of periprosthetic fractures with respect to biomechanical principles and furthermore provides an overview on implant augmentation.

Feasibility study on the potential of a spiral blade in osteoporotic distal femur fracture fixation.

INTRODUCTION: Osteoporotic fractures of the distal femur (primary as well as periprosthetic) are a growing problem in today's trauma and orthopaedic surgery. Therefore, this feasibility study should identify the biomechanical potential of a (commercially available) spiral blade in the distal femur as compared to a single screw without any additional plate fixation. Additionally, the influence of cement augmentation was investigated. MATERIALS AND METHODS: An artificial low density bone model was either instrumented with a perforated spiral blade or a 5 mm locking screw only. Additionally, the influence of 1 ml cement augmentation was investigated. All specimens were tested with static pull-out and cyclic loading (50 to 250 N with an increment of 0.1 N/cycle). RESULTS: In the non-augmented groups, the mean pull-out force was significantly higher for the blade fixation (p < 0.001). In the augmented groups, the difference was statistically not significant (p = 0.217). Augmentation could increase pull-out force significantly by 72 % for the blade and 156 % for the screw, respectively (p = 0.001). The mean number of cycles to failure in the non-augmented groups was 12,433 (SD 465) for the blade and 2,949 (SD 215) for the screw, respectively (p < 0.001). In the augmented group, the blade reached 13,967 (SD 1,407) cycles until failure and the screw reached 4,413 (SD 1,598), respectively (p < 0.001). CONCLUSION: The investigated spiral blade was mechanically superior, significantly, as compared to a screw in the distal femur. These results back up the further development of a distal femoral blade with spiral blade fixation for the treatment of osteoporotic distal femur fractures.

A laboratory investigation to assess the influence of cement augmentation of screw and plate fixation in a simulation of distal femoral fracture of osteoporotic and non-osteoporotic bone.

The augmentation of fixation with bone cement is increasingly being used in the treatment of severe osteoporotic fractures. We investigated the influence of bone quality on the mechanics of augmentation of plate fixation in a distal femoral fracture model (AO 33 A3 type). Eight osteoporotic and eight non-osteoporotic femoral models were randomly assigned to either an augmented or a non-augmented group. Fixation was performed using a locking compression plate. In the augmented group additionally 1 ml of bone cement was injected into the screw hole before insertion of the screw. Biomechanical testing was performed in axial sinusoidal loading. Augmentation significantly reduced the cut-out distance in the osteoporotic models by about 67% (non-augmented mean 0.30 mm (sd 0.08) vs augmented 0.13 mm (sd 0.06); p = 0.017). There was no statistical reduction in this distance following augmentation in the non-osteoporotic models (non-augmented mean 0.15 mm (sd 0.02) vs augmented 0.15 mm (sd 0.07); p = 0.915). In the osteoporotic models, augmentation significantly increased stability (p = 0.017).

[Treatment of periprosthetic and peri-implant fractures : modern plate osteosynthesis procedures]. / Versorgung periprothetischer und periimplantärer Frakturen : Moderne Plattenosteosyntheseverfahren.

Periprosthetic fractures are increasing not only due to the demographic development with high life expectancy, the increase in osteoporosis and increased prosthesis implantation but also due to increased activity of the elderly population. The therapeutic algorithms are manifold but general valid rules for severe fractures are not available. The most commonly occurring periprosthetic fractures are proximal and distal femoral fractures but in the clinical routine fractures of the tibial head, ankle, shoulder, elbow and on the borders to other implants (peri-implant fractures) and complex interprosthetic fractures are being seen increasingly more. It is to be expected that in the mid-term further options, such as cement augmentation of cannulated polyaxial locking screws will extend the portfolio of implants for treatment of periprosthetic fractures. The aim of this review article is to present the new procedures for osteosynthesis of periprosthetic fractures.

[Treatment of periprosthetic and peri-implant fractures : modern plate osteosynthesis procedures]. / Versorgung periprothetischer und periimplantärer Frakturen : Moderne Plattenosteosyntheseverfahren.

Periprosthetic fractures are increasing not only due to the demographic development with high life expectancy, the increase in osteoporosis and increased prosthesis implantation but also due to increased activity of the elderly population. The therapeutic algorithms are manifold but general valid rules for severe fractures are not available. The most commonly occurring periprosthetic fractures are proximal and distal femoral fractures but in the clinical routine fractures of the tibial head, ankle, shoulder, elbow and on the borders to other implants (peri-implant fractures) and complex interprosthetic fractures are being seen increasingly more. It is to be expected that in the mid-term further options, such as cement augmentation of cannulated polyaxial locking screws will extend the portfolio of implants for treatment of periprosthetic fractures. The aim of this review article is to present the new procedures for osteosynthesis of periprosthetic fractures.

Complex fractures of the proximal humerus in the elderly--outcome and complications after locking plate fixation.

Open reduction and internal fixation (ORIF) with locking plates or primary arthroplasty remains a controversial issue in the management of complex proximal humerus fractures. Aim of this study was to evaluate the surgeon- and patient-based outcome of patients older than 65 years who underwent ORIF using locking plate fixation of a 3- or 4-part fracture of the proximal humerus. Twenty-seven patients older than 65 years were treated with locking plate fixation (PHILOS, Fa. Synthes, Umkirch, Germany). At an average follow-up of 44 months, the clinical and the subjective outcome were evaluated, and complications were analyzed. The mean age- and gender-related Constant score was 70% (30­100%) compared with 92% (47­108%) of the contralateral non-injured shoulder. The mean DASH score was 29 points (0­71). Five patients (18.5%) showed clinical signs of an impingement, which was related to malpositioning of the plate in 3 cases. Screw cutout was seen in 22.2% (6 patients). Avascular necrosis of the head or the tubercula was found in 8 patients (29.6%). The revision rate was 29.6%. However, the patients considered the functional status of their shoulder as "good" or "satisfactory." The functional and patient-orientated results of the locking plate fixation of complex displaced proximal humerus fractures in the elderly are comparable to those of primary arthroplasty and minimally invasive treatment. Proper surgical technique (screw length, plate position) is mandatory for reducing the revision rate.

[Nonunion of the femoral neck and artificial heart. How far may we go?]. / Duokopfprothesenimplantation bei Schenkelhalspseudarthrose und liegendem Kunstherz. Wie weit darf man gehen?

Due to medical improvements surgeons are increasingly confronted with conditions associated with severe medical comorbidities. Fracture or nonunion of the femoral neck would have been classified as "inoperable" in the past. We report the successful operative treatment of a patient with femoral neck nonunion after screw osteosynthesis and associated existence of a left ventricular assist device for dilated cardiomyopathy.

Successful delayed surgical treatment of a scaphocapitate fracture.

The scaphocapitate fracture syndrome is a rare entity of a perilunate fracture-dislocation. The diagnosis is frequently missed at initial presentation to a physician. Usually, a CT scan is required to reveal the extent of the lesion. Operative treatment consists of open reduction and internal fixation with screws (e.g. headless compression screw) or Kirschner wires. We report on a case of a 19-year-old man who presented to our hospital 2 months after he fell on his left wrist. He complained about persistent pain and a decreased range of motion after conservative treatment in a short arm cast. The diagnosis was finally made by a CT scan and the patient was treated operatively using headless compression screws in both the capitate and the scaphoid. After 12 weeks, fractures were completely healed radiographically and the patient returned to work. At follow-up 16 months after trauma, the patient had no further complaints. Range of motion increased and no avascular necrosis could be observed.

[Tibial head fractures in the elderly]. / Tibiakopffrakturen im Alter.

In contrast to younger patients, tibial head fractures of the elderly usually result from minor trauma. In these patients, fractures of the tibial plateau are frequently seen and classified according to the Tscherne classification. In addition to plain radiographs which consist of an a.p. and a lateral view, a CT-scan is an obligatory part of the preoperative diagnostic. The therapeutic management is strongly depending on the psychic and physical condition of the patient, the fracture morphology, the decreased bone mineralization and the soft tissue damage. Low bone density requires rigid implants to provide a stable osteosynthesis. Metaphyseal defects have to be augmented with synthetic bone substitutes to avoid secondary loss of reduction. Early mobilization should be achieved to decrease the risk of serious complications.

Surgical separation of conjoined (Siamese) xiphopagus twins.

Conjoined twins of the xiphopagus type have been separated 24 hours after spontaneous delivery. Indication for early intervention was impending rupture of a large omphalocele as well as deterioration of one severely malformed twin who did not survive surgery, whereas the other one showed normal development up to 15 months after separation.