Varus Forces Research Articles

Radiographic and Functional Outcome of Depressed Tibial Plateau Fractures Treated with Raft Plate with Bone Graft – A Prospective Study

Tibial plateau fractures are the fractures that involve the articular surface of the tibial condyles. The Schatzker and OA classifications are the most commonly used to classify these fractures. The Schatzker classification system is a widely recognized method used by orthopedic surgeons to categorize tibial plateau fractures into six distinct types. This classification helps in assessing the initial injury, planning the appropriate management strategy, and predicting the prognosis. Each type represents a different pattern of fracture, which can guide treatment decisions and expectations for recovery. These fractures typically result from the external(valgus) or internal(varus) forces on the knee with axial loading. In younger individuals, tibial plateau fractures are most commonly caused by road traffic accidents due to the high-energy impact. However, in elderly patients with osteopenic bone, even a simple fall can lead to these fractures because their bones are more fragile and susceptible to injury. The tibial plateau fractures are intra-articular fractures of the knee joint and are often difficult to treat and have a high complication rate, including early-onset osteoarthritis. Surgery is the preferred modality of treatment for these fractures, along with bone void fillers to address bone defects caused by the injury. At present, there is no consensus on the optimal method of fixation or the void filling to treat such fractures. Techniques of operative management of tibial plateau fractures have become more successful in achieving and maintaining reduction of the fracture. Still, avoiding malalignment of the limb has been shown to be at least as important as articular congruity to long-term joint viability.

Functional outcome of internal fixation of tibial plateau fractures: an observational study

Background: Tibial plateau fractures are intra-articular fractures usually caused by high energy trauma either a valgus or varus force in combination with axial loading which affect the stability and function of weight bearing knee joint. Understanding the outcomes of surgical treatment for these fractures is crucial for both orthopaedic research and patient care. This study set out to examine the functional results of surgically managing tibial plateau fractures. Methods: This prospective observational study took place in the Department of Orthopedic Surgery at Bangabandhu Sheikh Mujib Medical University in Dhaka, Bangladesh, from January 2020 to December 2022. The study included 37 patients with tibial plateau fractures who underwent internal fixation. Data was analyzed using tools from Microsoft Office. Results: Among the study participants, 56.8% had an immobilization period of 1 week or less, and 32.4% were immobilized for 2-3 weeks. Complications included knee stiffness in 10.8% and malunion in 8.1% of cases. According to the Rasmussen grading system, 51.4% achieved an excellent outcome, 35.1% were categorized as good, while 8.1% and 5.4% fell into the fair and poor categories. Functional outcome was assessed by Oxford knee score is excellent 20 (54.5%), good 11 (29.7%), fair 4 (10.8%) and poor 2 (5.4%) respectively. Conclusions: Surgical treatment of tibial plateau fractures typically yields positive results in most cases. The use of internal fixation, particularly with locking compression methods, is considered an effective approach for treating these fractures. This technique is associated with a lower risk of complications and promotes efficient healing, contributing to favourable outcomes.

Astragalo-Scapho Calcaneal Dislocation and Literature Review

Introduction: The subtalar dislocations are rare, this is described as a dislocation of the talo-calcaneal and talo-navicular joints but the tibio-talar joint is intact. The diagnosis is easy and done with x-ray: antéro-posterior and lateral view. A emergency reduction is necessary In a few cases, you need a surgical approach if the dislocation is irreducible or no stable after reduction. Case Report: A man aged of 19 years, felt in climbing, with a forced varus. In emergency room, the clinical exam showed a deformation and the x-ray: a talo-naviculo-calcaneal dislocation. A reduction is done in the operative room, the testing a showed a stable ankle so we stabilized with a posterior splint. During the post-operative consultation: the control x-ray showed a good reduction and the CT: a minimal osteo-cartilagny tearing. The sport is authorized after three month. Conclusion: The talo-naviculo-calcaneal dislocation is rare following a plantar flexion and inversion. A diagnosis is quickly and easily done and the reduction is done in the operative room under general anesthesia. A cast is applied during some weeks before starting the physiotherapy. A surgical treatment is done in a few rare: irreducible – instable – open dislocation.

Anatomic reconstruction of the posteromedial corner of the knee: The Versailles technique

IntroductionMultiligament knee injury with posteromedial laxity is serious and usually requires surgery. Reconstruction is preferable to repair. The main aim of the present study was to report clinical results and laximetry for an original posteromedial corner (PMC) allograft reconstruction technique known as The Versailles Technique. The secondary aim was to determine prognostic factors for surgery. The study hypothesis was that anatomic PMC reconstruction by tendon allograft provides satisfactory medium-term clinical and laximetric results. MethodsA retrospective study assessed postoperative clinical and laximetric results after PMC allograft reconstruction at a minimum 12 months’ follow-up. Laxity was assessed on comparative bilateral stress X-rays, and functional results on the International Knee Documentation Committee (IKDC) score, the Lysholm score and the Knee injury and Osteoarthritis Outcome Score (KOOS). ResultsTwenty-six patients were included between 2013 and 2019. Mean follow-up was 27.4±9 months. Mean subjective IKDC score was 69.21±17.36, mean Lysholm score 77.78±14.98 and mean KOOS 66.44±18.52. ObjectiveIKDC results were 77% grade A, 22% grade B, and 0% grade C or D. Mean medial differential laxity in forced varus was 0.83±1.26mm. Mean subjective IKDC scores were poorer in Schenck KD-III than KD-I (p=0.03). Functional results were comparable with acute and with chronic laxity. Age correlated inversely with median KOOS (p=0.009). There was no correlation between postoperative radiologic laxity in forced varus and functional results. DiscussionVersailles anatomic PMC allograft reconstruction for acute or chronic posteromedial knee laxity showed medium-term efficacy in restoring good objective and subjective stability. Level of evidenceIV; retrospective observational study.

Comparison of antegrade and retrograde cross pin fixation in the surgical treatment of pediatric supracondylar femur fractures: A biomechanical study

PurposeThe aim of this study is to compare biomechanical stability of Kirschner wires (K-wires) sent with antegrade and retrograde technique in the fixation of pediatric supracondylar femur fractures. Materials and MethodsA transverse fracture model was created two centimeters above the physis in 24 synthetic bone models suitable for the pediatric femur bone structure. The models were randomly divided into two groups as 12 bones each. In the first group (Group 1), 12 bone fracture models were retrogradely fixed with two cross K-wires. In the second group (Group 2), the fracture was fixed antegradely. In Group 2, both wire ends were allowed to protrude three millimeters from the femoral condyles. The stability of the groups was tested biomechanically by exposing them to varus and extension forces. The forces corresponding to 1 mm, 2 mm, 3 mm and 4 mm displacement and failure loads were calculated in two groups. ResultsAccording to the test results regarding displacements and failure loads, the retrograde group was found to be significantly stronger than the antegrade group against varus loads (p < 0.05). When the groups were compared in terms of extension strength, the results of the two groups were similar and there was no statistical difference between them (p > 0.05). ConclusionRetrograde cross K-wires fixation provides a more stable fixation against varus forces. This is important to prevent varus deformity, which is a clinically less tolerable deformity. However, considering that full-weight mobilization of patients is not allowed after surgery in pediatric supracondylar femur fractures, the surgeon should consider that K-wires can also be sent antegrade to decrease the risk of septic arthritis.

Wedgeless V-Shaped Osteotomy of the Distal Medial Femur with Locking Plate Fixation for Correction of Genu Valgum in Adolescents and Young Adults.

Genu valgum is a common disorder affecting adolescents and young adults. Treatment of this disorder requires restoration of normal mechanical axis alignment and joint orientation, for which it is important to assess whether the deformity arises from the distal femur, knee joint, or proximal tibia. Most commonly, the deformity originates from the distal femur, and various osteotomies of the distal femur have been described1-6. The presently described wedgeless V-shaped osteotomy7,8 is a good option among the various alternative procedures listed below. The anesthetized patient is placed in the supine position on a radiolucent operating table. A bolster is placed beneath the knee to relax the posterior structures. A medial longitudinal skin incision is made that extends from the level of the medial joint line to 5 cm proximal to the adductor tubercle. The vastus medialis is identified and elevated anteriorly by detaching it from its distal and posterior aspects. The leash of vessels underneath the vastus medialis is identified, and the apex of the V-shaped osteotomy is kept just proximal to it. The anterior arm of the V is kept longer than the posterior one, both of them are kept perpendicular to each other, and the apex of the V is made to point distally. The osteotomy is performed on the medial cortex with use of an oscillating saw or multiple drill holes that are then connected using a thin osteotome. Care is taken not to utilize a saw or drill on the lateral cortex. A gentle valgus thrust is applied to break the lateral cortex without periosteal disruption. The apex of the V osteotomy on the proximal fragment is trimmed, and the deformity is corrected with varus force. The osteotomy site is stabilized with use of an anatomically contoured distal medial femoral locking plate or a medial proximal tibial L-shaped buttress plate (of the contralateral side). The implant position is verified under a C-arm image intensifier. The wound is closed in layers over a suction drain in a standard manner. Various types of corrective osteotomies of the distal femur have been described in the literature, including the lateral opening wedge, medial closing wedge, dome, and spike osteotomies1-6. All of these procedures have certain limitations and shortcomings. The wedgeless V-shaped osteotomy is another described procedure that is inherently stable7,8. It is a safe procedure and yields good clinical outcomes8,9. The posterior arm of the V-shaped osteotomy is kept smaller than the anterior arm. The proximal cortical bone is allowed to dig into the cancellous bone of the wider distal metaphysis during deformity correction. Trimming the apex of proximal bone end after making the osteotomy facilitates the process. In a study of 46 patients with a mean age of 16.9 years (range, 15 years to 23 years), Gupta et al.8 reported that the mean radiographic tibiofemoral angle improved from 22.2° (range, 16° to 29°) preoperatively to 5.1° (range, 0° to 10°) postoperatively (p < 0.001). Similarly, the mean lateral distal femoral angle improved from 79.2° preoperatively to 89.1° postoperatively (p < 0.001) and the mean mechanical axis deviation improved from 19.6 mm preoperatively to 3.7 mm postoperatively (p < 0.001). A total of 44 of 46 cases had an excellent functional outcome, with the other 2 having good outcomes. None of the patients in the study had an unsatisfactory outcome. It is important to keep the whole lower limb accessible to the image intensifier intraoperatively.Identification of the leash of vessels underneath the vastus medialis is important to decide the level of the osteotomy.It is important to preserve the periosteal sleeve on the lateral aspect of the femur. CORA = center of rotation of angulationECG = electrocardiogramLDFA = lateral distal femoral angleMAD = mechanical axis deviationMPTA = medial proximal tibial angle.

Biomechanical performance evaluation of a modified proximal humerus locking plate for distal humerus shaft fracture using finite element analysis

The extra-articular distal humerus plate (EADHP) has been widely used for surgical treatment of distal humerus shaft fracture (DHSF). However, the surgical approach, fixation methods, and implant positions of the EADHP remain controversial owing to iatrogenic radial nerve injury and complaints such as skin irritation related to the plate. Anterior plating with a modified (upside-down application) proximal humerus locking plate (PHILOS) has been proposed as an alternative, However, research on its biomechanical performance remain insufficient and were mostly based on retrospective studies. This study quantitatively compared and evaluated the biomechanical performance between posterior plating with the EADHP and anterior plating with a modified PHILOS using finite element analysis (FEA). The FEA simulation results that both the EADHP and PHILOS had adequate biomechanical performance and stability under axial, bending, and varus force load conditions. The PHILOS has a fixed stability comparable to that of the EADHP, and fixation was achieved using only four locking screws within a fixed range of 30 mm just above the olecranon fossa. The results show that the PHILOS could be an option for the fixation of a DHSF when considering the dissection range and complaints (e.g. skin irritation) associated with the EADHP.

A comparison of stiffness of six knee braces with application for posterolateral corner reconstructions.

Posterolateral corner knee injuries are clinically significant, and often require surgical reconstruction. The optimal knee brace following posterolateral corner reconstructions has not yet been determined via clinical nor biomechanical study. We sought to evaluate the stiffness of six types of knee braces to determine the ideal brace type for reducing varus forces, which may have clinical utility for posterolateral corner knee reconstruction rehabilitation. Six different groups of knee braces underwent mechanical testing: cruciate braces, cruciate braces with a valgus bend, medial unloaders, articulating sleeves, hinged braces, and tri-panel immobilizers. Each brace was fitted to the same fiberglass leg model and was secured to the testing apparatus. Force was applied under four-point bending to generate a varus moment about the artificial knee. The stiffness in Newtons per millimeter (N/mm) of each brace was calculated from the slope of the force-displacement curve. The cruciate brace with a valgus bend had the highest average stiffness at 192.61 N/mm (SD 28.53). The articulating sleeve was the least stiff with an average stiffness of 49.86 N/mm (SD 8.99). Stiffness of the cruciate brace was not statistically different compared to cruciate valgus (p = 0.083) or medial unloader (p = 0.098). In this experimental design, a cruciate brace with a valgus bend was shown to have the highest overall stiffness, while an articulating sleeve had the lowest stiffness. Future work will investigate whether this translates into clinical performance.

Biomechanical effects of internal fixation with self-lock compression anti-rotation blade for Pauwels type III femoral neck fractures: a comparative finite element analysis

BackgroundSelf-lock compression anti-rotation blade (SCAB) is a novel internal fixation implant for femoral neck fractures (FNF). We conducted this finite element analysis study to evaluate the biomechanical performances of SCAB combined with a cannulated screw for fixation of Pauwels type III FNF.MethodsThree finite element models of Pauwels type III FNF treated with various internal fixations were established: a: the inverted triangular parallel cannulated screw (3CS) model, b: the biplane double-supported screw fixation (BDSF) model, c: the SCAB combined with a cannulated screw model. Displacement and Von Mises stress of femurs and internal fixations under increasing loads as well as the average stress on fracture surfaces and maximum displacements on the X and Z axis of proximal fracture fragments at maximum load were measured and compared.ResultThe SCAB-based internal fixation exhibited superior biomechanical performances compared with 3CS and BDSF configurations, as the former resulted in lower parameters including displacement of the femur, Von Mises stress of internal fixation, stress on fracture surfaces as well as X and Z axis displacement of fracture fragments.ConclusionInternal fixation using SCAB combined with a cannulated screw for Pauwels type III FNFs shows enough stability, with satisfied resistance to varus and shearing forces, which may provide a new option for the treatment of FNFs.

Minimally Invasive Knee Lateral Collateral Ligament Reconstruction Using Partial Biceps Femoris Tendon Autograft

Lateral collateral ligament (LCL) is known as an important ligament to restrain varus force of the knee, especially in 30° knee flexion. From the anatomical study, the insertion of LCL at proximal fibula is intimately close to the insertion of biceps femoris (BF) tendon. Since LCL is infrequently injured in isolation, and with limitation in availability of autograft and allograft, this study proposes the partial anterior BF tendon as an alternative autograft source to reconstruct the LCL. This could be performed either by minimally invasive procedure or standard open technique. The core concept is to preserve the posterior part of the BF tendon to protect the peroneal nerve, by which exploration of this nerve and the proximal fibula prior to LCL reconstruction could be exempted. Minimally invasive LCL reconstruction using this autograft would essentially reduce soft tissue injury, shorten the operative time, and enhance recovery of the reconstructed knee.

Bone Bruise Patterns in Ligamentous Injuries of the Knee With Focus on Anterior Cruciate Ligament.

Introduction After sustaining an anterior cruciate ligament (ACL) injury, the bone bruises seen on magnetic resonance imaging (MRI) could reveal plenty of information regarding the loading mechanisms causing injury to the ACL. The current study was conducted to evaluate the common distribution patterns of bone bruises following an ACL injury and understand the loading mechanisms. Methods The knee MRI sequences of the patients operated arthroscopically for an injured ACL between August 2016 to August 2018 were selected for the study. The distribution pattern of the bone bruises was determined using the sagittal and coronal sections of MRI. The pattern of distribution of the bone bruises was categorized and analyzed by two independent observers. Results Twenty-two patients were found to have bone bruises diagnosed in the MRI scans. The mean age of the patients was 27.8 ± 8.7 years. The pattern of a bone bruises in only the lateral femoral and tibial compartments was the most typical pattern observed in this study. The study pattern has a significant anterior distribution of bone bruises on the outer (lateral) compartment of both the femur and tibia as compared to the inner (medial) compartment (p< .05 and p > .05, respectively). The inter-rater reliability between the two observers by Cronbach's Alpha was 93.2%. Conclusion Having the appropriate information regarding the pattern distribution of bone bruises and the concomitant injuries associated with it furthers our knowledge and helps us understand the loading mechanisms of ACL tears. A combination of coup forces acting on the lateral compartment and the contrecoup varus force on the medial compartment of the knee during the primary pivot-shift injury suggests an an involvement of multiplanar loading patterns at the point of sustaining ACL tear.

Meniscal extrusion under increasing varus in stress patients with a medial meniscus posterior root-tear.

Posterior root-tear of the medial meniscus and accompanied meniscal extrusion can lead to functional loss of the meniscus. The aim of this study is to assess medial meniscus extrusion at increasing varus forces utilizing magnetic resonance imaging (MRI), in order to evaluate the contribution of the adduction moment of the knee during gait. We prospectively enrolled 19 patients (38 knees). Patients underwent gait analysis testing to calculate adduction moment, followed by an MRI at rest and with increasing varus forces according to the patient's specific adduction moment. Meniscal extrusion and root gap at increasing varus forces were measured and compared. Functional outcomes and their association to meniscal extrusion was analyzed. We found the average meniscal extrusion at rest, 100% and 150% applied varus force for the control group to be 1.7mm, 1.7mm and 1.9mm, respectively; and for the index group average meniscal extrusion was 5.3mm, 6.4mm and 6.8mm, respectively. Meniscal extrusion increase from rest to 100% varus force was significantly higher in the index group (p=0.0002). Further meniscal extrusion and root gap increase from 100% varus force to 150% varus force did not show a statistically significant difference (p=0.39). The association between greater increase of meniscal extrusion with varus force and WOMAC scores was not statistically significant. In conclusion this study defines the contribution of the varus force component of the adduction moment to meniscal extrusion, in patients with a medial meniscus posterior root-tear.

Biomechanical comparison of elbow stability constructs.

Despite surgical stabilization of complex elbow trauma, additional fixation to maintain joint congruity and stability may be required. Multiple biomechanical constructs include a static external fixator (SEF), a hinged external fixator (HEF), an internal joint stabilizer (IJS), and a hinged elbow orthosis (HEO). The optimal adjunct fixation to surgical reduction is yet to be determined. Eight matched cadaveric upper extremities were tested in a biomechanical model. Anteroposterior stress radiographs were obtained of the elbow in full supination at 0° and 45° of elbow flexion with the weight of the hand serving as a varus load as the baseline. A 360° capsuloligamentous soft-tissue release was performed around the elbow. The biomechanical constructs were applied in the same sequential order: SEF, HEF, IJS, and HEO. For each construct, 0 kg (0-lb) and 2.3 kg (5-lb) of weight were applied to the distal arm. At both weights, radiographs were obtained with the elbow at 0° and 45° of flexion, with subsequent measurement of displacement, congruence at the ulnohumeral joint, and the ulnohumeral opening angle. Statistical analysis was performed to quantify the strength and stability of each construct. Compared with the control group at 0° with and without 2.3 kg (5-lb) of varus force and at 45° with and without 2.3 kg (5-lb) of varus force, no difference was noted in the medial ulnohumeral joint space, lateral ulnohumeral joint space, or ulnohumeral opening angle between the SEF, HEF, and IJS. The gap change after exertion of a 2.3-kg (5-lb) force between the control condition and application of each construct demonstrated no difference between the SEF, HEF, and IJS. Comparison among destabilized elbows showed no significant difference between the SEF, HEF, and IJS. The HEO catastrophically failed in each position at 0 kg (0-lb) of weight. The SEF, HEF, and IJS are neither superior nor inferior at maintaining elbow congruity with the weight of the arm and 2.3 kg (5-lb) of varus stress. The HEO did not provide additional stability to the unstable elbow.

Operative Fixation of the Anteromedial Facet of the Coronoid Process.

Anteromedial coronoid facet fractures typically occur with varus, pronation, and axial forces applied to the elbow. Due in part to the high rate of concomitant lateral collateral ligament (LCL) injuries, untreated anteromedial facet fractures can result in varus and posteromedial rotatory elbow instability. Although small fractures that are not amenable to open reduction and internal fixation can be treated with isolated LCL repair, larger fragments are treated with buttress plating on the anteromedial surface of the coronoid with or without LCL repair. The "over-the-top" approach via a split in the flexor pronator mass is the preferred method of accessing the anteromedial facet. Although data regarding the functional outcomes after operative fixation of the anteromedial facet are limited, observational studies have demonstrated good restoration of elbow stability and motion.

Functional Outcomes of Intra Articular Distal End Femur Fractures Treated with Locking Compression Plating

Background: Distal femur fractures represent 4-6% of all the femoral fractures and they occur within the 9 terminal centimeters. Most distal femur fractures are the result of a severe axial load with a varus, valgus or rotational force. Though various treatment options are available for the management of these injuries with their own advantages and disadvantages, treatment of these fractures with the angle stable constructs using Locking compression plating remains the most desirable treatment option. Objectives: To study the functional outcomes and complications of intra-articular distal end femur fractures treated with Locking Compression Plating. Materials and Methods: A prospective observational study was conducted over a period of 3 years on 47 patients requiring operational intervention for distal end femur fractures. Results: We studied different parameters like age of the patients, mode of injury, type of injury according to AO classification, duration of hospitalization, movement of knee after operation, Neer’s score results, union or non-union and compared our studies with other studies we find satisfactory results in our study in outcome of the patient As per the Neer’s knee score, excellent and good outcome was seen in 48.9% and 38.3% cases while fair and poor outcome was seen in 8.5% and 4.3% cases respectively. Conclusion: From our study we concluded that Distal femoral-LCP, the “internal fixator” was a safe and reliable implant although careful preoperative planning and case selection were important factors which determine the final outcome.

How can medial support for proximal humeral fractures be achieved when positioning of regular calcar screws is challenging? Slotting and off-axis fixation strategies.

Achieving medial support for proximal humeral fractures (PHFs) by regular calcar screw positioning is challenging when the humeral head is small or locking plates are placed distally, as there are unable inserted calcar screws into the humeral head. We aimed to investigate the suitability of the 2 strategies, slotting calcar screw (SCS) and off-axis calcar screw (OCS), to achieve medial support for PHFs. Regular calcar screw (RCS), SCS, OCS, and noncalcar screw (NCS) were tested via mechanical experiments and finite element analysis (FEA), using synthetic bones for biomechanical comparisons. All PHFs treated in our hospital from March 2017 to March 2019 were reviewed. The patients were divided into 3 groups based on the calcar screw fixation: RCS, SCS, and OCS. The postoperative varus collapse (neck-shaft angle changed to less than 120°) and Disabilities of the Arm, Shoulder and Hand (DASH) scores were recorded. The properties of RCS, SCS, and OCS against the torsion and varus force were superior to those of NCS, whereas the stiffness of SCS, OCS, and RCS were similar. FEA predicted lower peri-screw strains in the OCS and SCS than in the RCS, indicating a lower risk of cut-out. Patients (n = 125; 75 female, 50 male) aged 55.9 ± 13.0 years were evaluated. Compared with the RCS (5/55), varus collapse incidences were not significantly higher following SCS (0/29, P = .094) or OCS (3/41, P = .756), and neither were DASH scores (P = .867 and .736, respectively). This study is a preliminary study demonstrating that the SCS and OCS fixation strategies could be useful alternatives when regular calcar fixation is not possible using the plate at hand.

Clinical results after arthroscopic reconstruction of the posterolateral corner of the knee: A prospective randomized trial comparing two different surgical techniques

IntroductionArthroscopic reconstruction techniques of the posterolateral corner (PLC) of the knee have been developed in recent years. Reconstruction techniques for higher-grade PLC injuries have not yet been validated in clinical studies. This study aimed to compare clinical outcomes of two different techniques and to present results of the first prospective randomized clinical trial of patients to undergo these novel procedures.Materials and methods19 patients with Fanelli Type B posterolateral corner injuries and additional posterior cruciate ligament ruptures were included in this prospective study. They were randomly assigned to one of two novel arthroscopic reconstruction techniques, based on open surgeries developed by Arciero (group A) and LaPrade (group B). Follow-up was conducted at 6 and 12 months postoperatively and included clinical examinations for lateral, rotational and posterior stability, range of motion and subjective clinical outcome scores (IKDC Subjective Score, Lysholm Score, Tegner Activity Scale and Numeric Rating Scale for pain).ResultsAt 6 and 12 months postoperative, all patients in both groups presented stable to varus, external rotational and posterior forces, there were no significant differences between the two groups. At 12-month follow-up, group A patients showed significantly higher maximum flexion angles (134.17° ± 3.76° vs. 126.60° ± 4.22°; p = 0.021) compared to patients of group B. Duration of surgery was significantly longer in Group B patients than in group A (121.88 ± 11.63 vs. 165.00 ± 35.65 min; p = 0.003). Posterior drawer (side-to-side difference) remained more reduced in group A (2.50 ± 0.69 mm vs. 3.27 ± 0.92 mm; p = 0.184). Subjective patient outcome scores showed no significant differences between groups (Lysholm Score 83.33 ± 7.79 vs. 86.40 ± 9.21; p = 0.621).ConclusionsThis study indicates sufficient restoration of posterolateral rotational instability, varus instability and posterior drawer after arthroscopic posterolateral corner reconstruction without neurovascular complications.Increased postoperative range of motion and a shorter and less invasive surgical procedure could favor the arthroscopic reconstruction technique according to Arciero over LaPrade’s technique in future treatment considerations.

Revisiting Pauwels' classification of femoral neck fractures.

Pauwels’ femoral neck fracture classification is based on the biomechanical principle that shear stress and varus force increase along more vertically oriented fractures, resulting in higher risk of fracture displacement and ultimately nonunion. This principle continues to guide construct selection for femoral neck fracture internal fixation and is the foundation for treating non-union with valgus osteotomy. However, with poor inter- and intra-rater reliability, dated treatment recommendations, and unreliable prognostic value, the Pauwels classification cannot be directly applied in its entirety to the management of femoral neck fractures in modern practice.

Tibiofemoral dynamic stressed gap laxities correlate with compartment load measurements in robotic arm-assisted total knee arthroplasty.

AimsIt is unknown whether gap laxities measured in robotic arm-assisted total knee arthroplasty (TKA) correlate to load sensor measurements. The aim of this study was to determine whether symmetry of the maximum medial and lateral gaps in extension and flexion was predictive of knee balance in extension and flexion respectively using different maximum thresholds of intercompartmental load difference (ICLD) to define balance.MethodsA prospective cohort study of 165 patients undergoing functionally-aligned TKA was performed (176 TKAs). With trial components in situ, medial and lateral extension and flexion gaps were measured using robotic navigation while applying valgus and varus forces. The ICLD between medial and lateral compartments was measured in extension and flexion with the load sensor. The null hypothesis was that stressed gap symmetry would not correlate directly with sensor-defined soft tissue balance.ResultsIn TKAs with a stressed medial-lateral gap difference of ≤1 mm, 147 (89%) had an ICLD of ≤15 lb in extension, and 112 (84%) had an ICLD of ≤ 15 lb in flexion; 157 (95%) had an ICLD ≤ 30 lb in extension, and 126 (94%) had an ICLD ≤ 30 lb in flexion; and 165 (100%) had an ICLD ≤ 60 lb in extension, and 133 (99%) had an ICLD ≤ 60 lb in flexion. With a 0 mm difference between the medial and lateral stressed gaps, 103 (91%) of TKA had an ICLD ≤ 15 lb in extension, decreasing to 155 (88%) when the difference between the medial and lateral stressed extension gaps increased to ± 3 mm. In flexion, 47 (77%) had an ICLD ≤ 15 lb with a medial-lateral gap difference of 0 mm, increasing to 147 (84%) at ± 3 mm.ConclusionThis study found a strong relationship between intercompartmental loads and gap symmetry in extension and flexion measured with prostheses in situ. The results suggest that ICLD and medial-lateral gap difference provide similar assessment of soft-tissue balance in robotic arm-assisted TKA.Cite this article: Bone Jt Open 2021;2(11):974–980.

Magnetic resonance imaging (MRI) and Computed topography (CT) analysis of Schatzker type IV tibial plateau fracture revealed possible mechanisms of injury beyond varus deforming force

BackgroundSchatzker type IV tibial plateau fractures (type IV TPFs) are known for complex fracture morphology and high frequency of knee subluxation. Varus deforming force has been believed to be the cause but which fails to explain the lateral tibial plateau comminution and the lateral femoral condyle bone edema observed on injury MRI. The purpose of this study is to further explore the mechanisms of injury of type IV TPFs by synthetically analysing the information obtained from MRI and CT of a cohort of patients. MethodsBetween 2010 and 2019, 49 type IV TPFs were surgically treated in our hospital. The patients with complete preoperative CT and MRI were enrolled. They were classified according to OTA/AO and Luo's updated three-column classification (uTCC) after fracture morphology analysing and measuring. Then the injuries of cruciate/collateral ligaments and bone contusion were studied on MRI. The discrepancy between obvious fracture and occult bone contusion/soft tissue disruption among the groups of uTCC were compared and analysed. ResultsThirty patients were eligible for this study. Under uTCC system, all the cases were caused by varus force according to the tibial plateau angle and were classified into three groups of uTCC referring the posterior tibial slope angle: 4 were into hyperextension-varus, 21 into the extension-varus and 5 into the flexion-varus group. Fracture morphology analysis found in the extension-varus group, there were two distinct subgroups: OTA/AO 41B1.2 (medial+posteromedial columns disruption) and 41B3.3f (41B1.2 +posterolateral column disruption). Injury MRI revealed 28 of the 30 cases had more than 2 ligamentous injuries. The incidences of anterior and posterior cruciate injury were 96.7% and 43.3% respectively while 70% for medial collateral ligament (MCL). Eighteen out of 30 demonstrated apparent lateral femoral condyle bone contusion sign. Chi-square analysis found in the extension-varus group, the posterolateral column comminution was closely associated with lateral femoral condylar contusion (p<0.05) and MCL injuries (p<0.05). This finding and the absence of medial femoral condylar contusion was unlikely caused by uTCC proposed varus deforming force. ConclusionIn contrast to varus impaction, some type IV TPFs was probably caused by valgus or rotation force.