Varus Stress Radiographs Research Articles

Patient‐reported outcome measures following individualised TKA are not affected by the degree of preoperative coronal varus or valgus laxity

AbstractPurposeTo determine whether there is a correlation between preoperative coronal varus or valgus laxity and patient‐reported outcome measures (PROMs) 2 years after individualised total knee arthroplasty (TKA).MethodsRecords of 150 consecutive patients who received individualised TKA were retrospectively analysed, and 126 with complete pre‐ and postoperative data were included. Preoperative coronal varus and valgus stress radiographs (15 N load) were taken using a telos stress device with the knee in 5°–10° of flexion. Varus stress angles were positive if the joint opened on the lateral side, and valgus stress angles were positive if the joint opened on the medial side. The sum of varus and valgus stress angles indicated total joint laxity. During surgery, cases that required tibial recuts to balance the joint were recorded. Patients completed three PROMs and rated their satisfaction. Correlations between laxity and PROMs were evaluated using Pearson's correlation.ResultsStress radiographs revealed varus stress angles of 6.3° ± 3.5° (range, −4.5° to 14.1°), valgus stress angles of 0.1° ± 3.7° (range, −8.0° to 10.9°), and the sum of the varus and valgus stress angle of 6.4° ± 3.3° (range, 0.1° to 17.1°). There were no correlations between laxity and PROMs: r < 0.160 for varus stress angle, r < 0.180 for valgus stress angle and r < 0.160 for the sum of stress angles. There were no statistically significant or clinically relevant differences in PROMs between knees without and those with tibial recuts.ConclusionPreoperative coronal varus or valgus laxity was not correlated with PROMs following individualised TKA at a minimum 2‐year follow‐up. Individualised TKA with personalised alignment enables adequate accommodation of a broad spectrum of preoperative coronal varus–valgus laxities.Level of EvidenceIV

The Fibular Collateral Ligament Is a More Important Restraint to Varus Laxity Compared to the Anterolateral Complex in the Anterior Cruciate Ligament–Deficient Knee in a Cadaveric Biomechanical Study

PurposeThe purpose of this study was to compare the influence of the fibular collateral ligament (FCL) and the anterolateral complex (ALC) on varus knee laxity in paired anterior cruciate ligament (ACL)-deficient cadaveric knees using varus stress radiographs. MethodsVarus laxity in nine paired (N=18, mean age 73.8 years) human cadaveric knees was assessed using varus stress radiographs with a 12 Nm varus stress applied at 20° of knee flexion. All knees underwent testing in the intact state and following ACL sectioning. One knee of each pair was randomly assigned to undergo FCL sectioning and the contralateral knee was assigned to undergo ALC sectioning (anterolateral ligament [ALL] followed by the Kaplan fibers). ResultsBoth FCL sectioning and ALC (ALL and the Kaplan fibers) sectioning resulted in increased lateral compartment gapping compared to the intact state, 2.44 mm and 1.13 mm, respectively. ALL sectioning with intact Kaplan fibers did not result in increased lateral compartment gapping. Paired knee comparison revealed a significantly greater influence of the FCL than the ALC in restraining lateral compartment gapping under an applied varus stress (p=0.0003). ConclusionsSectioning the FCL resulted in significantly greater lateral compartment gapping under a varus stress than combined sectioning of the ALL and Kaplan fibers in an ACL deficient knee, although both scenarios resulted in significantly increased gapping compared to the intact state. Sectioning of the ALL with intact Kaplan fibers did not result in increased lateral compartment gapping. Clinical RelevanceThe FCL is the most important structure in restraining varus laxity in the ACL deficient knee and the ALC is of secondary importance in restraining varus laxity. In ACL deficient patients with a high-grade pivot shift, mild varus laxity on clinical examination, and an intact FCL on MRI, injury to the anterolateral complex should be considered and may be evaluated with varus stress radiographs. This study validates prior biomechanical studies of FCL deficiency and demonstrates that approximately 1 mm increase in lateral compartment gapping on varus stress radiographs may occur secondary to ALC injury and clinicians should be aware of this when considering treatment for ACL deficient patients with high-grade anterolateral laxity.

Comparing the Interobserver Reliability of 4 Methods Used to Measure Knee Laxity on Coronal Plane Stress Radiograph.

Varus and valgus knee stress radiographs provide valuable information in the pre- and postoperative evaluation of joint laxity in patients with multiligament knee injuries (MLKIs). To review the literature for described techniques of quantifying laxity on coronal stress radiographs of the knee and identify the most reliable method. Cohort study (diagnosis); Level of evidence, 3. A thorough literature search using the MEDLINE and Embase databases identified 4 studies with distinct methods for objectively measuring laxity on varus and valgus stress radiographs: Heesterbeek et al (2008), Jacobsen (1976), LaPrade et al (2004), and Sawant et al (2004). To compare these methods, 200 coronal plane stress radiographs from 50 patients with MLKIs were retrospectively reviewed from an MLKI database at a single institution. The amount of varus and valgus laxity on each radiograph was measured independently by 4 reviewers using each method. Intraclass correlation coefficients (ICCs) with 95% CIs were calculated to assess the interobserver reliability of each method overall and the varus and valgus measurements individually. For all 4 methods, the overall interobserver reliability was considered at least moderate. The method by Heesterbeek et al proved to have the highest interrater reliability in all domains-overall (ICC, 0.87 [95% CI, 0.85-0.90]), valgus (ICC, 0.83 [95% CI, 0.78-0.88]), and varus (ICC, 0.87 [95% CI, 0.83-0.90])-demonstrating good to excellent reliability both overall and in varus measurements and showing good reliability in valgus measurements. The method by Sawant et al demonstrated good reliability in valgus measurements. All other measures demonstrated moderate reliability. Available methods for measuring knee joint laxity on varus and valgus knee stress radiographs in patients with MLKIs demonstrated moderate to good interobserver reliability. The method described by Heesterbeek et al proved to have the highest reliability overall as well as in measurements on varus and valgus views individually.

Preoperative joint line obliquity, a newly identified factor for overcorrection, can be incorporated into a novel preoperative planning method to optimise alignment in high tibial osteotomy.

The aim of this study was to analyse the factors associated with additional postoperative alignment changes after accurate bony correction by selecting only patients with well-performed bony correction as planned and developa method of incorporating significant factors into preoperative planning. Among 104 consecutive patients who underwent medial open wedge high tibial osteotomy (MOWHTO) between October 2019 and July 2022, 61 with well-performed bony corrections were retrospectively reviewed. The major criterion for well-performed bony correction was a difference of <1° between the simulated medial proximal tibial angle (MPTA) and the actual postoperative MPTA as measured in three dimensions. Radiographic parameters, such as the joint line convergence angle (JLCA) and joint line obliquity (JLO), were measured preoperatively and postoperatively, utilising standing and supine whole lower extremity anteroposterior, valgusand varus stress radiographs. Multiple linear regression analysis identified the factors affecting alignment changes, and a prediction model was developed. A method for applying this prediction model to preoperative planning was proposed. Preoperative JLCA on standing (preJLCAstd ), preoperative JLCA on 0° valgus stress radiograph (vgJLCA0 ), and preoperative JLO (preJLO) were significantly correlated with JLCA change (∆JLCA) (p < 0.001, p < 0.001, p = 0.006). The prediction model was estimated as ∆JLCA = 0.493 × (vgJLCA0 ) - 0.727 × (preJLCAstd ) + 0.189 × (preJLO) - 1.587 in. (R = 0.815, modified R2 = 0.646, p < 0.001). The proposed method resulted in a reduced overcorrection rate (p = 0.003) and an improved proportion of acceptable alignments (p = 0.013). PreJLCAstd , vgJLCA0 and preJLO can be used to estimate ∆JLCA. PreJLO was recently identified as a significant factor associated with additional alignment changes. Utilising the proposed preoperative planning and a prediction model with these factors shows promise in calibrating postoperative alignment after MOWHTO. Level III, retrospective cohort study.

Higher success rate observed in reconstruction techniques of acute posterolateral corner knee injuries as compared to repair: an updated systematic review.

There remains controversy regarding the optimal surgical treatment for acute complete (grade III) posterolateral corner (PLC) injuries. The purpose of this article is to systematically review the contemporary literature regarding surgical options and subsequent outcomes of acute grade III PLC injuries. A systematic review was performed using the following search terms: posterolateral corner knee, posterolateral knee, posterolateral instability, multi-ligament knee, and knee dislocation. Inclusion criteria consisted of studies with level I-IV evidence, reporting on human patients with acute grade III PLC injuries undergoing operative management within 4weeks from injury, with subjective and/or objective outcomes (including varus stress examinations or varus stress radiographs) reported at a minimum 2-year follow-up. Two investigators independently performed the search by sequentially screening articles. Accepted definitions of varus stability on examination or stress radiographs and revision surgery were used to determine success and failure of treatment. A total of 12 studies, consisting of 288 patients were included. Ten studies reported primary repair, while reconstruction techniques were reported in seven studies. Overall, 43% (n = 125/288) of injuries involved the PLC, ACL and PCL. Staged reconstruction was reported in 25% (n = 3/12) of studies. The Lysholm score was the most commonly reported outcome measure. An overall failure rate of 12.4% (n = 35/282) was observed. Surgical failure was significantly higher in patients undergoing repair (21.9%; n = 21/96) compared to reconstruction (7.1%; n = 6/84) (p = 0.0058). Return to sport was greater in patients undergoing reconstruction (100%; n = 22/22) compared to repair (94%; n = 48/51) (n.s). The most common post-operative complication was arthrofibrosis requiring manipulation under anesthesia (8.7%; n = 25/288). A total of 3.8% (n = 11/288) of patients underwent revision PLC reconstruction. There remains substantial heterogeneity in the surgical techniques of acute, grade III PLC injuries with an overall failure rate of 12.4%. Failure rates were significantly lower, and return to sport rates higher in patients undergoing PLC reconstruction compared to repair. The most common postoperative complication was arthrofibrosis requiring manipulation under anesthesia. Level IV.

Osteotomy of the Femoral Lateral Collateral Ligament Insertion for a Tight Lateral Compartment in Complex Arthroscopic Knee Surgery

Background: In cases of complex arthroscopic knee surgery in the lateral compartment, such as performing lateral meniscus repair or transplantation, a tight lateral compartment can jeopardize the best possible care and could lead to iatrogenic cartilage injury. This technique shows a way to increase arthroscopic working space in a tight lateral compartment by performing an osteotomy of the femoral insertion of the lateral collateral ligament (LCL), utilizing a novel adjustable loop refixation technique. Indication: The femoral LCL insertion osteotomy can be performed if increased visualization and working space of the lateral compartment are needed during the complex arthroscopic knee surgery. Technique Description: After identification of the LCL femoral insertion, a 2-mm drill is passed through the LCL insertion to prepare for an anatomic reduction. The osteotomy is performed by taking a small bone plug together with the complete LCL insertion. Increased visualization and working space in the lateral compartment are obtained without damaging the intrinsic LCL structure. For reinsertion, the bone plug and proximal LCL is whipstitched with a high-strength suture and fixated to an adjustable loop Ultrabutton. The adjustable loop is shuttled through a predrilled 4.5-mm femoral tunnel and flipped on the medial side. The adjustable button is tensioned in 30° of flexion until the bone plug is anatomically reduced. Results: We present 1 patient who underwent a femoral LCL osteotomy during arthroscopic lateral meniscus allograft transplantation. The osteotomy healed without any issues, and there was no residual LCL laxity; which was confirmed with varus stress radiographs. Discussion/Conclusion: A femoral LCL insertion osteotomy can release a tight lateral compartment without damaging the intrinsic LCL structure. The adjustable loop fixation avoids the use of more traditional screw and washer fixation techniques, which tend to be more prominent and have the potential to back out. An osteotomy is more invasive than the “pie-crusting” technique of the medial collateral ligament for a tight medial compartment. However, it is required due to the poor intrinsic healing capacity of the LCL. Care should be taken to anatomically reduce the bone plug to avoid iatrogenic creation of LCL laxity. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Radiographic Measurements Correlate to Isolated Posterolateral Corner (PLC) Injury in a Novel Cadaveric Model.

Injury to the posterolateral corner (PLC) of the knee often requires surgical reconstruction. There remains no consensus on treatment for PLC injury, and, therefore, it is imperative to have a reproducible injury model to improve the general knowledge of PLC injuries. A novel cadaveric model of isolated PLC injury is proposed and evaluated using radiographic parameters as well as gross dissection. All protocols were reviewed by the Human Investigation and Research Committee of the home institution and were approved. Translational force in a defined posterior and lateral direction was applied to cadaveric native knees to induce PLC injury. Varus and recurvatum stress fluoroscopic imaging was obtained of each specimen before and after the injury model. Lateral joint distance and recurvatum angle after stress was measured on each image via picture archiving and communication software (PACS) imaging software. After the injury model, injured structures were assessed via saline loading and gross dissection. Any specimens found to be fractured were excluded from the analysis of stress radiography. A total of 12 knees underwent testing and 6/12 successfully induced PLC injury without fracture. The lateral capsule was torn in every specimen. The popliteofibular ligament (PFL) was torn in 83% of specimens and the fibular collateral ligament (FCL) in 66.7% of specimens. The median lateral gapping after injury under varus stress radiography was 5.39 mm and the median recurvatum angle after injury was 14.25°. Radiographic parameters had a direct relationship with a number of structures injured. This is the first successful cadaver model of PLC injury. The lateral capsule was injured in every specimen emphasizing the importance of this structure to the PLC.

Coronal Laxity at Flexion is Larger After Posterior-Stabilized Total Knee Arthroplasty Than With Cruciate-Retaining Procedures

BackgroundIt is unclear whether coronal stability differs between cruciate-retaining (CR) and posterior-stabilized (PS) total knee arthroplasty (TKA). The purpose of this study was to compare coronal laxity, radiological, and clinical outcomes between CR-TKA and PS-TKA. MethodsSeventy five CR-TKAs and 72 PS-TKAs with a minimum 2-year follow-up were retrospectively evaluated. Coronal laxity was assessed at knee extension and 80° of flexion on varus and valgus stress radiographs. Radiological evaluation included femoral-tibial angle, hip-knee-ankle angle, and positions of femoral and tibial components. Clinical evaluation included the modified Hospital for Special Surgery score, the Western Ontario and McMaster Universities Osteoarthritis index, and range of motion. ResultsPS-TKA resulted in significantly larger varus, valgus, and total laxities at 80° flexion (P = .034, .031, and 0.001, respectively) compared with CR-TKA, while no significant difference was found at extension (P = .513, .964, and .658, respectively). No statistical difference was found in radiological and clinical outcomes between CR-TKA and PS-TKA, but the functional scores were slightly better in CR-TKA. There were adverse correlations between varus laxity at flexion and the Western Ontario and McMaster Universities Osteoarthritis index, the modified Hospital for Special Surgery score, and range of motion (r = 0.933, −0.229, −0.472, respectively). ConclusionCoronal laxity at 80° of flexion was larger after PS-TKA than CR-TKA. In addition, clinical outcomes were adversely affected by the larger varus laxity at flexion. Care should be taken to maintain the coronal stability, especially at flexion, during surgery to obtain better patient-reported outcomes. Level of evidenceLevel III.

Effect of Sectioning of the Anterior Cruciate Ligament and Posterolateral Structures on Lateral Compartment Gapping: A Randomized Biomechanical Study.

Background:The contribution of anterior cruciate ligament (ACL) injury to lateral instability under varus stress, particularly compared with posterolateral structures, is not well known.Purpose:To investigate the effect of sectioning the ACL and posterolateral knee structures on lateral compartment gapping under varus stress.Study Design:Controlled laboratory study.Methods:Fourteen nonpaired cadaveric knees were randomized to 1 of 2 groups: sequential sectioning of the ACL, fibular collateral ligament (FCL), popliteus tendon (PLT), and popliteofibular ligament (PFL) (ACL-first group) or sequential sectioning of the FCL, PLT, PFL, and ACL (FCL-first group). Knees were loaded onto a custom jig at a 20° flexion angle. A standardized 12-N·m varus moment was applied to each specimen in the intact state and after each randomized sequential-sectioning state. Lateral compartment opening was measured on radiographs to assess the contribution to the increase in the lateral gap caused by resecting the respective structure. The distance was measured by 3 observers on 15 images (5 testing states each imaged 3 times) per specimen, for a total of 210 radiographs. The articular cartilage surfaces were not included in the measurements.Results:The mean increase in lateral opening after sectioning all structures (ACL and posterolateral corner) was 4.6 ± 1.8 mm (range, 1.9-7.7 mm). The ACL and FCL sectioning contributed the most to lateral knee opening (1.3 ± 0.6 and 2.2 ± 1.3 mm, respectively). In both groups, lateral gapping >3 mm was achieved only after both the ACL and FCL were sectioned. All comparisons of increased mean gapping distances demonstrated a significant difference with subsequent sequential sectioning of structures, except comparisons between the FCL and PLT and the PLT and PFL. When considering the effect of the ACL on lateral opening, no significant difference was found between sectioning the ACL first or FCL first (P = .387).Conclusion:ACL deficiency significantly increased lateral opening under varus stress, regardless of the sequence of injury. The effect of injury to the ACL in addition to the lateral structures should be considered when using varus stress radiographs to evaluate knee injuries.Clinical Relevance:With the current findings, understanding the effect of ACL and posterolateral corner injuries on lateral gapping under varus stress can aid in correctly diagnosing knee injuries and determining appropriate treatment plans.

Lateral Collateral Ligament and Biceps Femoris Tendon Fixation with a Suture Anchor to the Tibial Metaphysis after Proximal Fibula En Bloc Resections Preserve Lateral Knee Stability.

This study aims to analyze the functional outcomes and lateral knee stability of patients who underwent lateral collateral ligament (LCL) and biceps femoris tendon reconstruction with suture anchors after proximal fibula en bloc resection for bone tumors. Patients who underwent proximal fibular en bloc resection between 2007 and 2018 were retrospectively viewed. Patients were invited to visit the clinic, and their functional scores were evaluated using the Musculoskeletal Tumor Society Scoring (MSTS) system. Lateral knee stability was evaluated by varus stress radiographs obtained at 20 degrees of flexion, and the range of motion (ROM) of the bilateral knee was assessed. Side-to-side differences were graded according to the International Knee Documentation Committee (IKDC) criteria and compared between types I and II resections. A total of 17 patients (4 males and 13 females) with a mean age of 31.1 ± 17.1 (range: 13-65) years at the time of surgery were available for radiological and clinical examination at a mean follow-up of 68.6 ± 36.4 (range: 22-124) months after surgery. In terms of ROM measurements, IKDC grades and side-to-side differences in both flexion and extension were not significantly different between the groups. On varus stress radiographs, lateral knee gapping was measured to be 0.93 ± 0.91 mm in type-I resections and 1.83 ± 0.45 mm in type-II resections, and statistically significant differences were detected among the groups (p = 0.039). When the values were graded according to IKDC criteria, none of the knees were classified as abnormal, and no difference was observed between the groups. Mean MSTS score of patients with type-I resections was significantly higher than those of patients with type-II resections (92.7 vs. 84.4%, p = 0.021). In the subscale analysis, a significant difference was observed in the support scores (type I = 94.5%, type II = 70%; p = 0.001). The reattachment of LCL and biceps femoris tendon to the tibial metaphysis with a suture anchor is a simple and effective method to prevent lateral knee instability after proximal fibula resections.

Comparable Subjective and Objective Clinical Outcomes After Fibular or Combined Tibial-Fibular-based Reconstruction of the Posterolateral Corner of the Knee: A Systematic Review and Meta-analysis.

To compare subjective and objective outcomes of fibular and combined tibial-fibular (TF)-based posterolateral corner (PLC) reconstruction. A systematic review of literature reporting outcomes of posterolateral corner reconstruction was conducted including outcome studies of surgically treated PLC injuries with a minimum 1-year follow-up, postoperative subjective and objective outcomes including the patient-reported outcome scorings of Lysholm score, International Knee Documentation Committee evaluation (subjective and objective), dial test, and varus stress radiographs. The 32 studies included comprised 40 cohorts: 12 cohorts (n = 350 knees) used a fibular-based technique, and 28 cohorts (n = 593 knees) used a combined TF-based technique. No statistically significant differences were found in patient-reported outcomes or objective clinical measurements comparing the two techniques using the Lysholm score (P = 0.204, τ2 = 3.46), International Knee Documentation Committee evaluation (subjective P = 0.21 τ2 = 15.57; objective P = 0.398), dial test (P = 0.69), or varus stress radiographs (P = 0.98, τ2 = 0.08). This study found no statistically significant differences in subjective or objective clinical outcome measurements after fibular-based versus combined TF-based PLC reconstruction. Further prospective evaluation comparing long-term clinical outcomes, complications, and surgical time may help to elucidate a preferred reconstructive technique.

Revision TKA due to instability: diagnostics, treatment options and outcomes

Instability after primary TKA is afrequent reason for revision surgery. Other mechanisms of failure must be ruled out before an in-depth analysis of instability. Diagnostic tools for instability consist of medical history, clinical examination, and imaging. The clinical examination must focus primarily on the extent of the instability, the location of the instability and the levels of instability. Varus and valgus stress radiographs in the mediolateral plane in extension and flexion, as well as anteroposterior stress images (drawer) are mandatory. In addition, the underlying cause (or acombination of causes) must be defined. Possible causes include malalignment, component malposition (rotation), bony and ligamentous insufficiencies and implant-associated instabilities. Once the mechanism of failure is understood in detail, various therapeutic options are available. Conservative therapy is only considered in patients where there is borderline instability, and the patient has adequate compensatory options in daily life. Some authors postulate the need for 3months of conservative therapy in every case before possible surgery. Isolated inlay exchange is usually only acompromise and shows failure rates of up to 60%. Partial component exchange requires some preconditions and is technically demanding. If the indication is correct, the results are consistently comparable with those after full component revision. In the case of full component revision, attention must be paid to the degree of constraint to achieve stability but also to avoiding over-treatment (too highly constrained TKA with an probability of loosening). In general, the results after revision surgery are worse in cases of instability than in cases of exchange surgery due to aseptic loosening or patellar abnormalities but better than in cases of infection or arthrofibrosis.

Reconstruction of the Posterolateral Corner of the Knee Using LaPrade and Modified Larson Technique: A Prospective Study.

Posterolateral corner (PLC) injuries of the knee are often overlooked for its complex anatomy, and frequent association with cruciate ligament injuries. Overlooked injuries lead to reconstruction failure of cruciate ligaments, chronic knee pain and early arthritic changes. Many reconstruction methods are described, but the best treatment still remains elusive. In this study, we have treated grade-III PLC injuries by the 'anatomic LaPrade' technique and the 'fibula-based Modified Larson' technique, and evaluated their outcomes. Our hypothesis was that both the groups will have similar improvements after surgery. An open-label prospective comparative study was done with a total of 28 patients from August 2013 to July 2019. Patients were treated alternatively by LaPrade or Modified Larson technique using hamstring autografts. Follow-up visits were done at sixth week and subsequently at 3, 6, 12, 18 and 24months postoperatively. Outcomes were measured by Dial Test, side-to-side difference in lateral opening on varus stress radiographs, Lysholm score and IKDC subjective score. During analysis, we considered 25 patients only as three patients were lost to follow-up. Both the groups had comparable improvements in rotational stability, lateral opening on varus stress, Lysholm score and IKDC subjective score. Both LaPrade and Modified Larson technique showed good clinical results in restoring varus and rotational stability of knee in grade-III posterolateral corner injury of the knee. II (prospective, comparative study).

Consistency and Reliability of Ankle Stress Radiography in Patients With Chronic Lateral Ankle Instability.

Background:Ankle stress radiographs are important tools for evaluating chronic lateral ankle instability. The consistency of a patient’s ankle condition as it affects the reliability of ankle stress radiographs has never been evaluated.Purpose:To investigate the consistency and reliability of ankle stress radiographs in patients with chronic lateral ankle instability without an ankle injury during the study period.Study Design:Cohort study (diagnosis); Level of evidence, 3.Methods:Included were patients with chronic lateral ankle instability who underwent 2 repeated ankle stress radiographs between January 2014 and July 2019; those with an ankle injury during the study period were excluded. The tibiotalar tilt angle on varus stress radiographs and anterior translation of the talus on anterior drawer stress radiographs were measured at initial presentation and final follow-up examination. Interobserver reliability and consistency of ankle stress radiographs were analyzed using the intraclass correlation coefficient (ICC).Results:A total of 45 patients (mean ± standard deviation age, 36.4 ± 13.4 years; 18 men and 27 women; follow-up duration, 9.1 ± 3.2 months) were included. The mean ± standard deviation tibiotalar tilt angle and anterior talar translation at initial presentation were 10.8° ± 5.2° and 6.9 ± 2.7 mm, respectively. The interobserver reliabilities of the tibiotalar tilt angle and anterior talar translation were excellent (ICC = 0.926 [95% CI, 0.874-0.959] and 0.911 [95% CI, 0.766-0.961], respectively). The consistency between the initial and final radiographs was good for tibiotalar tilt angle (ICC = 0.763 [95% CI, 0.607-0.862]) and poor for anterior talar translation (ICC = 0.456 [95% CI, 0.187-0.660]).Conclusion:Although the interobserver reliability of the radiographic measurements was excellent, the consistency of the ankle stress radiographs was not as acceptable. Surgeons need to be cautious when deciding whether to operate on a patient with chronic lateral ankle instability based on a single ankle stress radiograph.

Stress Radiographs for Ligamentous Knee Injuries

Stress radiographs can provide an objective, quantifiable assessment of ligamentous knee injury. Commonly utilized techniques include varus, valgus, and posterior stress radiographs and can be used to augment findings on physical examination and magnetic resonance imaging. Both invitro and invivo studies have demonstrated reliability and validity of stress radiographs for diagnosing isolated and multiple ligament knee injuries. Varus stress radiographs are clinician applied at 20° flexion to detect injuries to the fibular collateral ligament and posterolateral corner. Valgus stress radiographs are clinician applied at 20° flexion to detect injuries to the medial collateral ligament or posteromedial corner. To evaluate the posterior cruciate ligament, posterior kneeling stress radiographs are obtained with the patient kneeling at 90° flexion on a firm platform. Bilateral radiographs are obtained and the side-to-side difference is compared to established criteria for injury severity. Stress radiographs support accurate diagnosis of complex knee injuries and also provide an objective measure of knee stability following ligament reconstruction. These imaging techniques can be performed in an ambulatory clinic setting with minimal additional equipment, and are thereby cost-effective, efficient, and support clinical decision-making in the treatment of complex knee injuries.

Stress radiography findings in medial meniscus posterior root tears

BackgroundThe present study aimed to evaluate stress radiography and magnetic resonance imaging (MRI) findings in medial meniscus posterior root tears (MMPRTs). MethodsThe study included 27 patients (26 females, mean age, 53.52 years) who underwent high tibial osteotomy and in whom medial menisci were concurrently examined arthroscopically. Preoperative stress radiographs and MRI series in 14 cases with root tears (MMPRT group, detected arthroscopically) and in 13 cases without tears (control group) were evaluated. Joint spaces measured on the stress radiographs were compared between the operated and opposite knees in each group. ResultsOn the varus stress radiographs, the mean lateral joint space of the operated knees was significantly wider than that of the opposite knees in the MMPRT group (P = 0.007). Upon MRI studies, meniscal extrusion was significantly more common in the MMPRT group than in the control group. Moreover, the amount of meniscal extrusion was correlated with the tear size. ConclusionsWidening of the lateral joint space on the varus stress radiography was higher in the cases with root tears. Therefore, we propose that stress radiographs can be helpful in the diagnosis of MMPRT.

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.

Proximal Tibiofibular Dislocation in a Closing-Wedge High Tibial Osteotomy Causes Lateral Radiological Gapping of the Knee: A Prospective Randomized Study.

Background: To determine whether a proximal tibiofibular joint dislocation (TFJD) increases lateral compartment gapping more than a fibular head osteotomy (FHO) during a closing-wedge high tibial osteotomy (CWHTO). The second objective was to determine whether lateral compartment gapping affects clinical outcomes. Methods: A prospective randomized clinical study was carried out that included 18 patients in Group 1 (FHO) and 18 in Group 2 (TFJD). Varus-stress radiographs of all the patients with both knees at full extension and at 30° of flexion were studied pre-operatively and 12 months post-operatively. Lateral compartment gapping was measured in millimeters. The Knee Society Score (KSS) was used to assess clinical stability. Results: The difference between the pre- and post-operative measurements relative to gapping in the lateral knee compartment at 0° of knee flexion was 1.3 mm (SD 1.8) in Group 1 and 4.5 mm (SD 2.4) in Group 2 (p = 0.006). At 30° of knee flexion, this difference was 1.9 mm (SD 1.2) in Group 1 and 5.2 mm (SD 3.1) in Group 2 (p = 0.01). No differences were observed in the pre- and post-operative period relative to gapping in healthy knees. Pre-operatively, both groups presented similar KSS knee values: Group 1 with 54.7 (SD 11.7), Group 2 with 54.8 (SD 11.1) (n.s.). Post-operatively, these values were also similar: Group 1 with 93.2 (SD 7.4), Group 2 with 93.5 (SD 5.5) (n.s.). Conclusions: In patients who have undergone a CWHTO, TFJ dislocation increases knee lateral compartment gapping when compared to an FHO at 0° and 30° of knee flexion. However, this fact seems to have no repercussion on the functional status of the knees as measured with the KSS at the one-year follow-up.

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 kneesMethods: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

Intraoperatively accurate limb alignment after opening wedge high tibial osteotomy can be lost by large knee joint line convergence angle during surgery.

The purpose of this study was to assess early postoperative loss of achieved correction and associated factors after opening wedge high tibial osteotomy (OWHTO). OWHTO was performed in 121 patients with osteoarthritis of the knee (mean age 66years, 154 knees). Anteroposterior radiographs of the knee and full-length leg, and varus and valgus stress radiographs of the knee were taken, and the femorotibial angle (FTA), joint line convergence angle (JLCA), and medial proximal tibial angle (MPTA) were measured. The changes in the FTA, JLCA, and MPTA were defined as ΔFTA, ΔJLCA, and ΔMPTA. The ΔFTA and ΔJLCA at postoperative 0-2days were - 1.8 ± 1.2° and - 1.9 ± 1.4°, respectively. The ΔFTA, ΔJLCA and ΔMPTA at postoperative 1-12months were 0.9 ± 1.3°, 0.2 ± 1.2° and - 0.8 ± 0.8°, respectively. A positive correlation was found between ΔFTA and ΔJLCA at postoperative 0-2days (ρ = 0.642, P < 0.001) and at postoperative 1-12months (ρ = 0.402, P < 0.001). A negative correlation was found between ΔFTA and ΔMPTA at postoperative 1-12months (ρ = - 0.534, P < 0.001). A discrepancy in alignment represented by the FTA occurred in the supine radiographs between the day of surgery and postoperative 2days. Multiple regression analysis suggested that postoperative JLCA on the day of surgery was the factor related to early postoperative change of the FTA. This study demonstrated the early loss of achieved correction after OWHTO due to change of the JLCA, even if the accurate alignment is obtained intraoperatively.