The treatment of posterolateral knee instability with combined arthroscopic popliteus bypass and PCL reconstruction provides good-to-excellent clinical results in the mid-term follow-up.

PURPOSE: The purpose of this study was to evaluate the clinical outcomes of patients who were treated with an arthroscopic popliteus bypass (PB) technique, in cases of a posterolateral rotational instability (PLRI) and a concomitant posterior cruciate ligament (PCL) injury of the knee. METHODS: This was a retrospective case series in which 23 patients were clinically evaluated after a minimum of 2 years following arthroscopic PB and combined PCL reconstruction. Lysholm, Tegner and Knee Injury and Osteoarthritis Outcome scores as well as visual analog scales (VAS) for joint function and pain were evaluated. Posterior laxity was objectified with stress radiography and a Rolimeter examination. Rotational instability was graded with the dial test. RESULTS: 23 patients were available for follow-up, 46.0 ± 13.6 months after surgery. The median time interval from the initial injury to the surgery was 6.0 (3.5;10.5) months. The postoperative Lysholm Score was 95.0 (49-100); the Tegner Score changed from 6.0 (3-10) before the injury to 5.0 (0-10) at the follow-up examination (p = 0.013). The side-to-side difference on stress radiography (SSD) of posterior translation changed from 10.4 (6.6-14.8) mm before the injury to 4.0 (0.2-5.7) mm postoperatively (p < 0.01). Rotational instability was reduced to grade A (82.6%) or B (17.4%) (IKDC). The Rolimeter SSD was 2.0 (0-3) mm at the follow-up examination. VAS Function 0 (0-5), VAS pain 0 (0-6). CONCLUSIONS: The arthroscopic PB graft technique provided good-to-excellent clinical results in the mid-term follow-up in patients with type A PLRI and concomitant PCL injury. However, an exact differentiation of lateral, rotational and dorsal instabilities of posterolateral corner (PLC) injuries is crucial, for the correct choice of therapy, as cases with lateral instabilities require more complex reconstruction techniques. Arthroscopic posterolateral corner reconstruction is a safe procedure with a high success rate in the mid-term follow-up. LEVEL OF EVIDENCE: IV.

The Popliteus Bypass provides superior biomechanical properties compared to the Larson technique in the reconstruction of combined posterolateral corner and posterior cruciate ligament injury.

PURPOSE: This study aimed to compare the biomechanical properties of the popliteus bypass against the Larson technique for the reconstruction of a combined posterolateral corner and posterior cruciate ligament injury. METHODS: In 18 human cadaver knees, the kinematics for 134 N posterior loads, 10 Nm varus loads, and 5 Nm external rotational loads in 0°, 20°, 30°, 60,° and 90° of knee flexion were measured using a robotic and optical tracking system. The (1) posterior cruciate ligament, (2) meniscofibular/-tibial fibers, (3) popliteofibular ligament (PFL), (4) popliteotibial fascicle, (5) popliteus tendon, and (6) lateral collateral ligament were cut, and the measurements were repeated. The knees underwent posterior cruciate ligament reconstruction, and were randomized into two groups. Group PB (Popliteus Bypass; n = 9) underwent a lateral collateral ligament and popliteus bypass reconstruction and was compared to Group FS (Fibular Sling; n = 9) which underwent the Larson technique. RESULTS: Varus angulation, posterior translation, and external rotation increased after dissection (p < 0.01). The varus angulation was effectively reduced in both groups and did not significantly differ from the intact knee. No significant differences were found between the groups. Posterior translation was reduced by both techniques (p < 0.01), but none of the groups had restored stability to the intact state (p < 0.02), with the exception of group PB at 0°. No significant differences were found between the two groups. The two techniques revealed major differences in their abilities to reduce external rotational instability. Group PB had less external rotational instability compared to Group FS (p < 0.03). Only Group PB had restored rotational instability compared to the state of the intact knee (p < 0.04) at all degrees of flexion. CONCLUSION: The popliteus bypass for posterolateral reconstruction has superior biomechanical properties related to external rotational stability compared to the Larson technique. Therefore, the popliteus bypass may have a positive influence on the clinical outcome. This needs to be proven through clinical trials.

Patients' expectations of osteotomies around the knee are high regarding activities of daily living.

PURPOSE: This study was conducted to investigate patients' expectations on high tibial osteotomies, distal femur osteotomies, and double-level osteotomies in different health-related domains. It was hypothesized that expectations are high in terms of capacity to work, pain relief, and restoring knee function. METHODS: A total of 264 patients (age 47 years ± 11 years) were enrolled in this study from March 2015 until May 2016 in seven specialized orthopaedic surgery departments. Data were collected via the Knee injury and Osteoarthritis Outcome Score, the Hospital for Special Surgery-Knee Surgery Expectations Survey, and a ten-item (non-validated) questionnaire to specifically ask about expectations of osteotomies around the knee 24-48 h prior to surgery. In addition, self-efficacy was assessed. Parametric tests were used to test the hypothesis. RESULTS: Knee injury and Osteoarthritis Outcome Score test results showed that all patients suffered because of their knee impairments prior to surgery. All participants had high expectations in all aspects regarding the surgical outcome: on a four-point Likert scale ranging from 1 (very important) to 4 (not important), all mean values were between 1.2 and 1.7. For patients who had a demanding physical work, the ability to keep a stressful working posture was more important than for other patients (i.e. to kneel, to squat). Furthermore, preoperative lower quality of life was associated with higher expectations concerning improving the ability to walk, to achieve improvements in activities of daily living and social well-being. CONCLUSIONS: Patients' expectations of osteotomies around the knee are high in terms of capacity to work, pain relief, and restoring functions. The natural course of osteoarthritis and the potential need for conversion to TKA were underestimated by a substantial proportion of the study population. However, the expectation regarding survival rate is in line with the reported literature. The results of this study should assist surgeons in discussing realistic expectations when considering and counselling patients regarding osteotomies around the knee. This may help to clarify realistic expectations preoperatively and ultimately improve patients' satisfaction. LEVEL OF EVIDENCE: Therapeutic study, Level II.

Patella height is not altered by descending medial open-wedge high tibial osteotomy (HTO) compared to ascending HTO.

PURPOSE: The primary purpose of the study was to gain insight into geometric changes of the patellar height (PH) and posterior tibial slope (PTS) after a biplanar ascending medial open-wedge high tibial osteotomy (HTO) compared to biplanar descending medial open-wedge HTO in patients with genu varum. METHODS: Sixty-four patients (mean age 45.2 ± 8.7 years, females n = 24, males n = 40) with varus malalignment and medial gonarthrosis were retrospectively studied. Patients received either a biplanar ascending or descending medial open-wedge HTO. Radiographic analysis included the assessment of standing total leg axis, PH, and PTS prior to and after surgery. RESULTS: In the ascending HTO group, PH decreased significantly by 4.0% (p = 0.037, Caton-Deschamps index) after an average leg axis valgus-producing correction of 7.1° ± 2.8°. In the descending HTO group, with an average leg axis correction of 7.0° ± 3.7°, there were no significant PH changes. There were no significant differences between the ascending and descending HTO groups regarding PTS or leg axis. The mean post-operative leg axis between ascending (1.6° ± 1.9°) and descending HTO (1.9° ± 2.4°) was not significantly different. CONCLUSION: Compared to the biplanar ascending medial open-wedge HTO, the descending HTO did not influence patella height or increase the posterior tibial slope. In order to respect patellofemoral and slope-related knee kinematics, a biplanar descending medial open-wedge HTO has proven useful to control patella height and posterior tibial slope. These findings underscore the importance of the preoperative patella height assessment in the osteotomy planning and subsequent choice of the biplanar osteotomy direction. LEVEL OF EVIDENCE: IV.

Arthroscopic reconstruction of the popliteus complex: accuracy and reproducibility of a new surgical technique.

PURPOSE: With combined PCL reconstruction and a minimal invasive (extra-anatomical) Larson's procedure, dorsal instability can be reduced by about 50-70 %. Better results are described by open and more anatomical procedures. In this study, a new, standardized, arthroscopic technique for anatomical popliteus tendon (PLT) reconstruction is evaluated. METHODS: In 13 cadaver knees, an arthroscopic reconstruction of the PLT and the lateral collateral ligament was performed. Twelve defined landmarks were used for arthroscopic tunnel placement, and the distance of the tunnel locations to these specific landmarks was evaluated. RESULTS: The femoral drill channel was located with a high degree of accuracy and reproducibility in the centre of the femoral footprint of the PLT (on average 1.1 (±1.6) mm distal from the centre). On the tibial side, the drill channel was in the distal third of the sulcus popliteus in all cases. On average, the channel was placed exactly at the level of the tip of the fibula (±1.5 mm) and 0.6 (±1.7) mm medially from the medial edge of the fibula. The centre of the channel was 13.4 (±2.3) mm distal from the joint line. CONCLUSIONS: The presented arthroscopic technique for PLT reconstruction is standardized, reproducible and has a high accuracy for the placement of the tibial and femoral tunnel. The technique could be clinically relevant for future arthroscopic posterolateral corner reconstructions. LEVEL OF EVIDENCE: III.

Primary ligament sutures as a treatment option of knee dislocations: a meta-analysis.

PURPOSE: Treatment of knee dislocation is still controversial. There is no evidence to favour ligament suture or reconstruction. Until now, no meta-analyses have examined suture versus reconstruction of cruciate ligaments in knee dislocations with respect to injury pattern and rupture classification. METHODS: We searched Medline, the Cochrane Controlled Trial Database, and EMBASE for studies on surgical treatment for 'knee dislocation' and 'multiple ligament injured knee'. A meta-analysis was performed using individual patient data. RESULTS: Nine studies including 195 patients (200 knees) with a mean age of 31.4 (±13) years fulfilled the study requirements. Thirteen cases of type II dislocations, 63 cases of type III medial, 84 cases of type III lateral, and 40 cases of type IV dislocations, according to Schenck's classification, were found. Poor or moderate results were found in 70 % of patients without surgical treatment of ACL or PCL (n = 27). Patients (n = 40) treated by sutures of the ACL and PCL demonstrated a significantly greater proportion of excellent or good results (40 and 37.5 %, respectively) (p < 0.001). Patients who underwent reconstruction of the ACL and PCL (n = 75) showed excellent or good results (28 and 45 %, respectively). No significant difference was found when comparing suture versus reconstruction of the ACL and PCL (n.s.). The outcome depends considerably on Schenck's injury pattern classification. CONCLUSION: Conservative treatment after knee dislocation yields poor clinical results. Suture repair of cruciate ligaments can still serve as an alternative option for multiligament injuries of the knee and achieve good clinical results, which are comparable to those of ligament reconstruction. The data provided by this meta-analysis should be reinforced by a prospective study, in which suture repair and ligament reconstruction are compared. LEVEL OF EVIDENCE: IV.

[Bouldering: a sport with a high risk of intraarticular fractures]. / Bouldern ­ Trendsport für jedermann mit Potential zu schwerwiegenden Gelenkverletzungen.

Bouldering is a famous new sport with an increasing number of athletes. It became an Olympic sport in 2020. As no major sports equipment is required, everybody can take up bouldering even with little knowledge. However, despite the low climbing height there is a high risk of severe joint injuries, especially in the lower limb. Increasing numbers of climbers have led to an increase in injuries. New floor designs are supposed to reduce these risks. Improved documentation and specific research in bouldering should provide more insight into risks, injury patterns and prevention.

Posterolateral Rotatory Knee Instability-MRI Evaluation of Anatomic Landmarks for Tibial Drill Tunnel Placement in Open and Arthroscopic Popliteus Tendon Reconstruction.

Anatomic reconstruction of the popliteus tendon and arcuate complex results in superior functional and a biomechanically more stable outcome compared with extra-anatomic techniques in posterolateral rotatory knee instability. Although specific characteristics of the femoral and fibular footprint of the anatomic posterolateral reconstruction have been described, data for tibial tunnel placement while popliteus tendon reconstruction do not exist. The purpose of this study was to quantify reasonable parameters, which could be used in arthroscopy, fluoroscopy, or open surgery to determine the anatomic tibial drill tunnel position in popliteus tendon reconstruction. Thirty magnetic resonance images of 30 patients with an intact posterolateral corner (PLC) were analyzed to specify the ideal point for tibial fixation of a popliteus tendon graft with respect to 17 bony, cartilaginous, and ligamentous anatomic landmarks. The ideal point for tibial fixation was defined as the musculotendinous junction of the popliteus tendon near to the insertion of the popliteofibular ligament. In the coronal plane, the ideal tibial fixation was located at the crossing of a tangent to the fibular head, parallel to the joint line with a tangent to the medial border of the fibular head, and vertical to the joint line with a deviation of less than 1 mm. It was located 0.26 (±1.91) mm superior to the distal edge and 11.75 (±2.66) mm lateral to the lateral edge of the tibial posterior cruciate ligament footprint and only 8.68 (±2.81) mm lateral to the lateral edge of the neurovascular bundle. Interrater reliability to detect the correct position of the popliteus tendon graft footprint was almost perfect. The position for tibial drill tunnel placement in anatomic popliteus tendon reconstruction showed low interindividual differences. The present findings of the quantified anatomic landmarks might improve open, fluoroscopy, or arthroscopy guided PLC reconstruction.

"Fracturoscopy" is Superior to Fluoroscopy in the Articular Reconstruction of Complex Tibial Plateau Fractures-An Arthroscopy Assisted Fracture Reduction Technique.

OBJECTIVE: To analyze the anatomic accuracy of fracture reduction controlled by fluoroscopy as compared with arthroscopically assisted reduction ("fracturoscopy") in patients with complex tibial plateau fractures (AO/OTA 41-C). Quality of fracturoscopy-guided reduction was checked with postoperative computed tomography. DESIGN: Prospective observational study. SETTING: Urban level 1 trauma center. PATIENTS: Seventeen consecutive patients, with a complex, bicondylar tibial plateau fracture. INTERVENTION: The intraoperative, open insertion of an arthroscope (2.4-mm or 2.8-mm optics), to visualize the articular surface and fracture reduction. MAIN OUTCOME MEASUREMENTS: Ability to detect residual fracture depression or gap after previous open reduction under fluoroscopic guidance. RESULTS: An open fracture reduction with fluoroscopic guidance was performed in all cases. In 7 cases, open reduction and fluoroscopy resulted in satisfactory fracture reduction (fluoroscopy group). In 10 of 17 cases, subsequent "fracturoscopy" showed persistent fracture depression (≥2 mm, fracturoscopy group) with the need for intraoperative correction. Patients in the fracturoscopy group demonstrated significantly greater preoperative fragment depression (12.55 ± 6.56 mm) and a larger preoperative fracture gap (7.83 ± 5.49 mm) compared with patients with a satisfactory reduction under fluoroscopy (depression 4.97 ± 4.02 mm, P = 0.016; gap 2.47 ± 1.07 mm, P = 0.023). Fluoroscopy was not successful in achieving satisfactory reduction in cases in which the postero-latero-central region was affected (P = 0.004, χ test). Postoperative computed tomography demonstrated satisfactory articular reconstruction in all cases. CONCLUSIONS: Intraoperative fracturoscopy permitted a significantly improved visualization of fracture fragment displacement, specifically in the postero-latero-central region of the tibial plateau, as compared with fluoroscopy. Fracturoscopy is recommended for fractures involving the postero-latero-central region of the tibial plateau. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Intra-articular tibial plateau fracture characteristics according to the "Ten segment classification".

BACKGROUND: Currently existing classifications of tibial plateau fractures do not help to guide surgical strategy. Recently, a segment-based mapping of the tibial plateau has been introduced in order to address fractures with a fracture-specific surgical approach. The goal of the present study was to analyze incidence and fracture specifics according to a new 10-segment classification of the tibial plateau. METHODS: A total of 242 patients with 246 affected knees were included (124 females, 118 males, mean age 51.9±16.1years). Fractures were classified according to the OTA/AO classification. Fracture pattern was analyzed with respect to a 10-segment classification based on CT imaging of the proximal tibial plateau 3cm below the articular surface. RESULTS: 161 Patients suffered an OTA/AO type 41-B and 85 patients an OTA/AO type 41-C tibial plateau fracture. Females had an almost seven times higher risk to suffer a fracture due to low-energy trauma (OR 6.91, 95% CI (3.52, 13.54), p<0.001) than males. In 34% of the patients with affection of the medial tibial plateau, a fracture comminution, primarily due to low-energy trauma (p<0.001), was observed. In type B fractures, the postero-latero-lateral (65.2%), the antero-latero-lateral (64.6%) and the antero-latero-central (60.9%) segment were most frequently affected. Every second type C fracture showed an unique fracture line and zone of comminution. The tibial spine was typically involved (89.4%). A typical fracture pattern of high-energy trauma demonstrated a zone of comminution of the lateral plateau and a split fracture in the medial plateau. The most frequently affected segments were the postero-latero-central (85.9%), postero-central (84.7%), and antero-latero-central (78.8%) segment. CONCLUSION: Posterior segments were the most frequently affected in OTA/AO type B and C fractures. Acknowledging the restricted visibility of posterior segments, whose reduction and fixation is crucial for long-term success, our findings implicate the use of posterior approaches more often in the treatment of tibial plateau fractures. Also, low-energy trauma was identified as an important cause for tibial plateau fractures.

Gentamicin supplementation of polyvinylidenfluoride mesh materials for infection prophylaxis.

Hernia repair evolved from pure tissue repair to mesh repair due to decreased recurrence rates. However, concern exists about mesh-related infections occurring even several years after initial operation. Therefore, a polyvinylidenfluoride (PVDF) mesh material was constructed and surface modified by plasma-induced graft polymerization of acrylic acid (PVDF+PAAc). Antimicrobial treatment was sought by binding of gentamicin (PVDF+PAAc+Gentamicin). In vitro efficacy and cytotoxicity was measured by agar diffusion test, L929 cytotoxicity testing and by analyzing the amount of gentamicin release from the mesh surface. In vivo biocompatibility was evaluated in 45 Sprague-Dawley rats. 7, 21 and 90 days after mesh implantation the amount of inflammatory and connective tissue as well as the percentage of proliferating (Ki67) and apoptotic cells (TUNEL) were analyzed at the perifilamentary region. Agar diffusion tests showed sufficient local antimicrobiotic effects against the bacteria tested after 24h of incubation. No signs of cytotoxicity could be identified by L929 testing. Furthermore, surface modification did not affect the in vivo biocompatibility. At the end of the observation period, no significant differences were found for the perifilamentary amount of inflammatory cells and connective tissue and the percentage of Ki67 and TUNEL positive stained cells. The presented data confirm that an antibiotic surface modification of PVDF mesh samples is feasible. By analyzing cytotoxicity in vitro as well as biocompatibility in vivo no side effects were observed.