Ultrasonographic Measurement of Elbow Varus Laxity With a Sequential Injury Model of the Lateral Collateral Ligament–Capsular Complex

Background: There is no consensus how to determine the varus laxity due to the LCL injury using the ultrasonography. There is a risk of lateral collateral ligament injury during or after arthroscopic extensor carpi radialis brevis release for tennis elbow. The equator of the radial head has been suggested as a landmark for the safe zone to not increase this risk; however, the safe zone from the intra-articular space has not been established. Hypothesis: Increased elbow varus laxity due to lateral collateral ligament–capsular complex (LCL-cc) injury could be assessed reliably via ultrasound. Study Design: Descriptive laboratory study. Methods: Eight cadaveric elbows were evaluated using a custom-made machine allowing passive elbow flexion under gravity varus stress. The radiocapitellar joint (RCJ) space was measured via ultrasound at 30° and 90° of flexion during 4 stages: intact elbow (stage 0), release of the anterior one-third of the LCL-cc (stage 1), release of the anterior two-thirds (stage 2), and release of the entire LCL-cc (stage 3). Two observers conducted the measurements separately, and the mean RCJ space in the 3 LCL-cc injury models (stages 1-3) at both flexion angles was compared with that of the intact elbow (stage 0). We also compared the measurements at 30° versus 90° of flexion. Results: At 30° of elbow flexion, the RCJ space increased 2 mm between stages 0 and 2 (95% confidence interval [CI], 1-3 mm; P < .01) and 4 mm between stages 0 and 3 (95% CI, 2-5 mm; P < .01). At 90° of elbow flexion, the RCJ space increased 1 mm between stages 0 and 2 (95% CI, 1-2 mm; P < .01) and 2 mm between stages 0 and 3 (95% CI, 2-3 mm; P < .01). Conclusion: Elbow varus laxity under gravity stress can be reliably assessed via ultrasound by measuring the RCJ space. Clinical Relevance: Because ultrasonographic measurement of the RCJ space can distinguish the increasing varus laxity seen with release of two-thirds or more of the LCL-cc, the anterior one-third of the LCL-cc, based on the diameter of the radial head, can be considered the safe zone in arthroscopic extensor carpi radialis brevis release for tennis elbow.

Postoperative laxity of the lateral soft tissue is largely negligible in total knee arthroplasty for varus osteoarthritis

Purpose: To evaluate the integrity of lateral soft tissue in varus osteoarthritis knee by comparing the mechanical axis under varus stress during navigation-assisted total knee arthroplasty before and after compensating for a bone defect with the implant. Methods: Sixty-six knees that underwent total knee arthroplasty were investigated. The mechanical axis of the operated knee was evaluated under manual varus stress immediately after knee exposure and after navigation-assisted implantation. The correlation between each value of the mechanical axis and degree of preoperative varus deformity was compared by regression analysis. Results: The maximum mechanical axis under varus stress immediately after knee exposure increased in proportion to the degree of preoperative varus deformity. Moreover, the maximum mechanical axis under varus stress after implantation increased in proportion to the degree of preoperative varus deformity. Therefore, the severity of varus knee deformity leads to a progressive laxity of the lateral soft tissue. However, regression coefficients after implantation were much smaller than those measured immediately after knee exposure (0.99 vs 0.20). Based on the results of the regression formula, the postoperative laxity of the lateral soft tissue was negligible, provided that an appropriate thickness of the implant was compensated for the bone and cartilage defect in the medial compartment without changing the joint line. Conclusion: The severity of varus knee deformity leads to a progressive laxity of the lateral soft tissue. However, even if the degree of preoperative varus deformity is severe, most cases may not require additional procedures to address the residual lateral laxity.

An isolated Posterolateral corner injury with rotational instability and hypermobile lateral meniscus: a novel entity

Purpose Although complete tear of the knee posterolateral corner (PLC) commonly occurs in combination with other knee ligamentous injuries, the incidence of isolated PLC injury was reported only 28% and overlooked in many cases. Nevertheless, an isolated PLC injury does not only provoke posterolateral instability, but also may be associated to hypermobile lateral meniscus. This study aims at showing the characteristics of isolated PLC injuries and to alert potential overlooked cases by describing their arthroscopic findings and clinical characteristics. Methods Seventy-one patients with a clinically proven isolated PLC injury who underwent knee arthroscopy were included in this study. Pre-operative symptoms and clinical signs at examination were recorded: Pain at the posterolateral aspect, feelings of instability, catching, locking; and for clinical signs: McMurray test, varus stress test in extension and at 30° of flexion, posterolateral drawer test at 30° and 80°, dial test at 30° and 80° of flexion. In terms of arthroscopic findings, systematic meniscal stability was performed to evaluate the presence of hypermobile lateral meniscus, “lateral drive through test” was also recorded in all cases. Results Positive Lateral Drive through test was found in 69 patients (95.8%). Hypermobile lateral meniscus was seen in all patients. Conclusions Hyper mobile lateral meniscus was concomitant with all isolated PLC injuries in our case series. As the typical arthroscopic characteristic, lateral drive through test positive were seen in 95.8%. In order to prevent overlooking this concomitant pathology, meticulous arthroscopic observation is crucial. Level of evidence Level IV.

Fractures of the Humeral Ulnar Condyle in Children – a Rare but Complicated Injury

Background Ulnar humeral condyle fractures are rare paediatric elbow fractures, classified as Salter-Harris IV paediatric elbow injuries. Due to constant radiological changes in the elbow with varying manifestation of ossification centres as well as late ossification of the trochlea, diagnosis of these injuries is challenging. To avoid long-term complications, the treating surgeon should be familiar with the rare injury picture, diagnostics and adequate therapeutic measures. Material and Methods The present retrospective study includes data on all paediatric cases from 2002 to 2019 with primary or secondary treatment at a paediatric traumatology centre for ulnar condyle fracture with a minimum follow-up of 12 months. Range of motion, joint stability under valgus and varus stress as well as axial ratios of the injured and uninjured side were evaluated in a clinical follow-up examination. The Mayo Elbow Performance Score was used to objectify functional results. Results 20 children, average age 8.6 years (4 – 13) and average follow-up time 25 months, were included. Radiological evaluation based on Jakob and Fowles classification revealed a type I fracture in three cases, a type II fracture in one case and a type III fracture in 16 cases. Three cases were treated nonoperatively with an upper arm cast. 17 children were treated with open reduction and internal fixation. Diagnosis of three fractures was delayed. No postoperative complications such as infections, nerve damage or nonunions. 15 children showed free elbow function. Three children showed slightly restricted elbow extension by less than 10° and two by 10°–20°. All children showed free pro/supination. 18 children showed a physiological and bilaterally identical arm axis compared to the uninjured side. Two children showed a slightly increased cubitus valgus with a 5 – 10° difference between sides. Radiologically, two children with delayed fracture treatment showed partial necrosis of the trochlea. The Mayo Elbow Score showed good (2) to excellent results in all children (18). Conclusion Very good clinical and functional results can be expected if the injury is diagnosed without delay followed by adequate therapy. Misdiagnosis of ulnar condyle fractures can be associated with the development of nonunions and functional restrictions as well as, after operative therapy, trochlear necrosis. Children up to the age of 6 in particular are at risk of misdiagnosis due to faulty assessment of the cartilaginous trochlea.

Biomechanics and physical examination of the posteromedial and posterolateral knee: state of the art

The posteromedial and posterolateral corner structures contribute significantly to knee stability. The posterior oblique ligament is a primary restraint to internal rotation and a secondary restraint to valgus. The superficial fibres of the medial collateral ligament are the primary valgus restraint and also provide secondary internal and external rotation stability. The deep fibres of the medial collateral provide additional restraint to internal and external rotation as well as valgus. The posteromedial capsule provides a secondary restraint to valgus and posterior translation. The lateral (fibular) collateral ligament is the primary varus stabiliser. The popliteus tendon complex is a primary restraint to external rotation. The popliteofibular ligament is a secondary restraint to external rotation and varus. Many physical examination manoeuvres have been described to assess these structures. Manoeuvres assessing the posterolateral structures include the varus stress test, dial test, the posterolateral drawer, the external rotation recurvatum test, heel height test and the reverse pivot shift. Examination manoeuvres that assess the posteromedial structures include the valgus stress test, dial test, anterolateral drawer test and anteromedial drawer test. Proper application of physical examination manoeuvres in conjunction with other diagnostic modalities will allow providers to develop appropriate treatment plans.

Anatomic Lateral Collateral Ligament Reconstruction Graft Options: Clinical and Radiographic Outcomes of Autograft versus Allograft

Objectives: As awareness of lateral knee pathology has increased, surgical outcomes for lateral collateral ligament (LCL) reconstruction and posterolateral corner reconstructions have improved. Despite reliable improvement in results, no study to date has compared the radiographic or clinical outcome of lateral knee reconstruction procedures when comparing autograft versus allograft reconstruction options. To evaluate patient reported outcomes and radiographic outcomes following anterior cruciate ligament (ACL) reconstruction with isolated LCL anatomic reconstruction, comparing the use of autografts versus allografts for LCL reconstruction. The null hypothesis was that there would be no significant differences in clinical outcomes at 2-year follow up and no differences in LCL insufficiency as defined by a side-to-side difference of greater than 2.1mm in varus stress radiographs at minimum of 6-month follow up. Methods: All patients who underwent primary ACLR with concomitant isolated LCL reconstruction from 2010 to 2017 by a single surgeon were retrospectively identified; clinical characteristics and graft choice for LCL reconstruction was collected. Patients with minimum 2-year follow up clinical outcome scores and 6-month bilateral varus stress radiographs were included. Patients with any other ligamentous procedure or revision ACL reconstruction were excluded. An a priori power analysis demonstrated a minimum group size of 18 patients per group to detect a difference in LCL insufficiency. Results: There were 58 primary ACLR with concomitant LCL reconstruction patients identified that met inclusion criteria. Thirty-nine patients underwent LCL reconstruction with semitendinosus autograft compared to 19 patients with allograft (16 semitendinosus and 3 tibialis anterior). At a minimum 6-month radiographic varus stress x-ray follow-up, there was no significant difference in LCL graft reconstruction failure (>2.1 mm) between autograft and allograft (autograft 0/39 vs allograft 0/19). There was also no absolute side-to-side difference of stress x-ray gapping between the two cohorts (allograft= 0.49 mm and autograft= 0.15 mm, p= 0.22). Furthermore, there was no difference when comparing the autograft to allograft group at minimum 2-year clinical outcome follow-up for SF-12 Mental Component Score (MCS) and Physical Component Score (PCS), WOMAC (Total, pain, stiffness, activity), Tegner, and Lysholm scores. Lastly, patient satisfaction between allograft and autograft groups showed no significant difference at average follow-up of 3.6 years. There were no significant differences in clinical knee stability between groups at final follow-up (p >0.05). Conclusion: In the largest reported series comparing autograft and allograft lateral collateral ligament reconstructions, we found that both autograft and allograft LCL reconstructions offer reliable and similar radiographic and clinical results. As a result, surgeons may discuss the risks and benefits of both graft options with the patient and come to a decision through a shared decision-making process knowing that both grafts will provide reliable outcomes.

Comparative Biomechanical Study Between Minimally Invasive Popliteus and LCL Reconstruction Versus LaPrade Technique

Background: Many aspects of the posterolateral corner (PLC) of the knee have been extensively studied within the past 20 years. Quantitative anatomic and biomechanical studies have demonstrated the importance of the 3 static stabilizers of the lateral side of the knee: the fibular collateral ligament, the popliteus tendon, and the popliteofibular ligament. There are various methods of reconstruction. However, currently, there is no consensus on the preferred reconstruction technique for treating patients with chronic PLC injuries. We have developed a new reconstructive technique for PLC based on tibiofibular-based technique, similar to LaPrade, and this technique is less invasive than the previous techniques. Hypothesis: There is no difference between minimally invasive popliteus and LCL reconstruction and LaPrade’s method in restoring the posterolateral stability of knees Methods: Six paired fresh-frozen cadaveric knees were assessed in the intact state and then dissected to simulate a grade III posterolateral knee injury. By using a “Blocked randomization”, each paired knee was randomized into 2 groups (1) reconstruction via LaPrade’s method, (2) minimally invasive popliteus and LCL reconstruction. Biomechanical testing using varus stress radiographs was performed to compare knee stability between 2 groups. Results: This study included six paired knees, three males and three females. The mean age of the cadaver was 70.8 years (range 57-85 years). No difference was found in the demographic data (sex distribution, lateral opening gap of intact knee and side-to-side difference of lateral opening gap of sectioned knee) between the 2 groups. The side-to-side difference in lateral joint opening on the varus stress radiographs significantly improved after PLC reconstruction in both groups (p <0.001, p <0.001), However, there were no differences between the 2 groups in side-to-side difference of lateral opening gap after reconstruction (Mean difference=-0.05 (95%CI, -0.46 to 0.36); p- value=0.039). Conclusion: Biomechanically, minimally invasive popliteus and LCL reconstruction is equivalent to LaPrade’s technique in restoring the stability of knees in case of grade III PLC injury. Additionally, this technique is less invasive than all traditional open technique of PLC reconstruction. The minimally invasive popliteus and LCL reconstruction technique may be a treatment option for grade III PLC injury. Keywords: posterolateral corner; ligament reconstruction; popliteus tendon; lateral collateral ligament; popliteofibular ligament; knee biomechanics; minimally invasive surgery

Opposite Association Between Radiographic Lateral Ankle Instability and Osteochondral Lesions of the Talus in Patients with Ankle Inversion Injuries

Category: Ankle Introduction/Purpose: Insufficient bony coverage surrounding the talus could cause considerable mechanical ankle instability, whereas excessive bony coverage could cause bone contusion at the time of injury and subsequent osteochondral lesions of the talus (OLT). This study aimed to investigate the relationship between radiographic lateral ankle instability and OLT in patients that sustained ankle inversion injuries. Methods: One-hundred-ninety-five patients (113 men and 83 women; mean age, 38.7 years; standard deviation, 8.8 years) with a history of ankle inversion injuries were included. All patients underwent ankle magnetic resonance imaging (MRI) and stress X-ray (varus stress and anterior drawer) examination. The tibiotalar tilt angle on varus stress X-ray, anterior translation of the talus on anterior-drawer lateral X-rays, bimalleolar tilt angle, and fibular position were radiographically determined. The anatomical grade of the lateral ankle ligament injury and the presence of OLTs were determined from MRI findings. Results: A greater lateral ankle ligament grade tends to increase the tibiotalar tilt angle (p=0.074), significantly affecting the anterior translation of the talus (p=0.036). The presence of radiographic lateral ankle instability (tibiotalar tilt angle =10°) showed opposite associations with the presence of OLT in the chi-square test (p=0.003). OLT was a negative significant factor (p=0.011) affecting the tibiotalar tilt angle in the multiple regression analysis (Table 1) and was negatively affected by the tibiotalar tilt angle (p=0.016) in the binary logistic regression analysis. Conclusion: This study showed an opposite association between lateral ankle instability and the development of OLT following ankle inversion injury. The role of bony predisposition in the development of sports injuries in the ankle should be considered and investigated further.