Magnetic resonance imaging quality in the context of a knee-spanning external fixator placed inside the MR bore: a literature review

After emergent assessment of potentially limb-threatening injuries in knee dislocation or multi-ligament knee injury patients, magnetic resonance imaging is necessary to visualize ligamentous structures and plan for soft tissue repair. However, the application of a knee-spanning external fixator may introduce artifact and reduce overall image quality, which can limit the evaluation of soft tissue injury. As a result, the utility of MRI in the context of a knee-spanning external fixator has been called into question. Signal-to-noise ratio, contrast-to-noise ratio, and qualitative scales have been used to assess image quality of MRI in the context of a knee-spanning external fixator. Despite the potential for artifact, studies have demonstrated that useful diagnostic information may be obtained from MRI in the presence of an external fixator. This review examines the general principles of anatomical assessment, magnetic field strength, device composition and design, radiofrequency coil use, and MRI sequences and artifact reduction as they pertain to MRI in the presence of a knee-spanning external fixator.

Incidence and type of meniscal tears in multilligament injured knees

PURPOSE

Meniscal injuries occurring during multi-ligament knee injuries (MLKI) are underreported. The purpose of this study was to compare the incidence and type of meniscal tears seen at the time of multi-ligament reconstruction surgery compared to those occurring during isolated anterior cruciate ligament (ACL) surgery.

METHODS

Patients undergoing surgical treatment for MLKI and ACL-only injuries between 2010 and 2020 were reviewed. Two-hundred and thirty-five patients were included in the MLKI group. There were 131 chronic injuries and 104 acute injuries. Two-hundred and twenty-two ACL-only chronic injuries were used as a control group for comparison with the chronic MLKI group. Demographic data, type of meniscal tears, ligament injury patterns (Schenck classification) and time from injury to surgery were recorded. A delayed procedure was defined by a 4-week interval after the knee injury.

RESULTS

A meniscus was torn in 69 knees (29.4%): 36 knees (15.3%) with an isolated medial meniscus tear, 33 knees (17.9%) with an isolated lateral meniscus tear,.Nine knees (3.8%) had both menisci torn. MLKI with medial or lateral-sided bicruciate ligament injuries (KDIIIM-KDIIIL) were significantly associated with a lower rate of meniscal tears than knee injuries involving the ACL-only and medial/lateral-sided ligament injuries (KDI) (medial-sided injuries p = 0.025; lateral-sided injuries p = 0.049). Lateral-sided injuries had significantly less meniscal damage than medial-sided injuries: 22/124 (17.7%) vs. 41/100 (41%); (p < 0.001). No significant differences were found for frequency, type and distribution of meniscal tears between acute and chronic MLKI surgery. ACL-only chronic injuries were associated with a higher rate of meniscal tears: 123/222 knees (55.4%) vs. 35/131 (26.9%) chronic MLKI; (p < 0.001), mainly involving the medial meniscus: 102/222 (46%) vs. 18/131 (13.7%); (p < 0.001).

CONCLUSIONS

Meniscal tears were less common in the MLKI group than in the isolated ACL injury group. The degree of ligament injury patterns and the side of the injured collateral ligament influenced the type and incidence of meniscal damage. Contrary to isolated ACL injuries, a delayed procedure was not associated with a higher rate of meniscal lesions but did influence the type of treatment. Understanding of meniscal tears patterns in MLKI helps to improve the treatment management of these complex injuries.

Low rate of return to pre-injury level of sports after multi-ligament knee injury - Functional outcomes after MLKI

BACKGROUND

Multi-ligament knee injury (MLKI) is a rare but severe injury with potential devastating complications. The primary goal of this study was to investigate return to sports and work after MLKI. Secondary outcomes were patient reported outcome measures (PROMs), treatment, time between trauma, diagnosis and treatment, and neurovascular damage.

METHOD

A database search was performed to identify all patients with MLKI in our hospital (2010-2017). Pre-defined variables were collected from patient files and questionnaires. Multiple regression analysis was used to study the relationship between different variables and PROMs.

RESULTS

31 patients were included. The overall return to sports rate after a MLKI was 88.5%, but only 23.1% returned to their pre-injury level. 83.3% of the patients were able to return to work. Multiple regression analyses led to a significant prediction model for pain during rest (F(7,16) = 2.808, p = 0.041, R² = 0.355). Within this model, a higher age was a significant predictor for higher pain scores (p = 0.002). Age was also a significant (negative) predictor within the non-significant models for IKDC (p = 0.004) and Lysholm (p = 0.024). A delay between trauma and diagnosis of more than three months was seen in 32.3% of the patients.

CONCLUSIONS

This study showed a relatively high overall return to sports and work after MLKI, but less than a quarter returned to their pre-injury level of sports. An important finding was the substantial number of patients with a delay between trauma and diagnosis. This study contributes to more awareness and knowledge about MLKI among physicians, which is essential to reduce these delays.

Open approaches for cruciate ligament reconstruction in knee dislocations: A technical note and case series

INTRODUCTION

Arthroscopic surgery is the gold standard for cruciate ligament reconstruction in multi-ligament knee injuries. However, hospitals in limited-resource settings often lack arthroscopic-trained surgeons or equipment. Open approaches for treating knee dislocations can overcome many of these limitations.

METHODOLOGY

This study aims to describe techniques for open approaches in a supine patient to address the cruciate ligaments in multi-ligament knee injuries and to review associated complications and clinical outcomes in a retrospective case series.

RESULTS

Ten patients with multi-ligament knee injuries who had undergone open cruciate ligament reconstruction between July 2016 and November 2018 were retrospectively identified. Open approaches were performed owing to the extravasation of arthroscopy fluid into the posterior compartment (3) or a large traumatic arthrotomy (7). Complications and patient-reported outcomes were analysed. Eight of the 10 patients were followed up at 10 months postoperatively (range, 5-23 months). None had iatrogenic neurovascular damage. Median outcomes scores were: visual analogue scale, 45 (range, 0-100); Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form, 81.4 (range, 75-100); Lysholm, 85 (range, 67-92).

DISCUSSION

Open approaches were safe and useful in treating cruciate ligaments and should be considered in arthroscopy fluid extraversion and large traumatic arthrotomies.

MULTI-LIGAMENT KNEE RECONSTRUCTION AND NOVEL MENISCUS RADIAL REPAIR TECHNIQUE, WITH RETURN TO OLYMPIC LEVEL SKIING: A CASE REPORT

BACKGROUND AND PURPOSE

Multi-ligament knee injuries (MLKI) can be debilitating and often career ending injuries for athletes. Current literature reports on outcomes following these injuries for return to activities of daily life; however, there is a paucity of evidence evaluating the return to sport following a MLKI. The purpose of this case report is to describe the treatment and outcome following a MLKI and novel meniscus radial repair technique in which the athlete returned to compete in the 2018 Winter Olympic Games 14 months postoperatively.

STUDY DESIGN

Case Report.

CASE DESCRIPTION

A healthy 28-year-old female Olympic alpine skier who sustained a deep knee flexion with varus force injury to her right knee during a competitive skiing event. Examination and imaging revealed a completely torn anterior cruciate ligament (ACL) and lateral collateral ligament (LCL), complex radial tear of the lateral meniscus, medial meniscus tear, popliteofibular ligament tear, proximal tibiofibular joint ligament tear, and a common peroneal nerve neuropraxia. The athlete underwent an anatomic single-stage, multi-ligament knee reconstruction surgery which consisted of a novel meniscus radial repair technique.

OUTCOMES

A return to snow progression was initiated at seven months postoperatively. At 10 months postoperatively, a physical exam revealed trace effusion, no joint line tenderness, and negative stability tests. A repeat MRI revealed adequate healing of the lateral meniscus radial repair. The athlete passed a functional sports test at 10-months postoperatively and was cleared to return to ski with no restrictions. At 12 months postoperatively, the athlete placed in an Olympic qualifying ski race. At 14 months postoperatively, the athlete competed in the 2018 Olympic Winter Games.

DISCUSSION

This case report highlights the ability of an athlete to return to elite level of competition following an anatomic single-stage, multi-ligament knee reconstruction with a novel meniscus radial repair in a safe but timely manner.

LEVEL OF EVIDENCE

4.

Bicruciate lesion biomechanics, Part 1-Diagnosis: translations over 15 mm at 90° of knee flexion are indicative of a complete tear

PURPOSE

Understanding the pathomechanics of a bicruciate injury (BI) is critical for its correct diagnosis and treatment. The purpose of this biomechanical study aims to quantify the effects of sequential sectioning of the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) bundles on knee laxity.

METHODS

Twelve cadaveric knees (six matched pairs) were used. Knee laxity measurements consisted of neutral tibial position, anterior-posterior translation, internal-external rotation, and varus-valgus angulation in different conditions: intact, ACL cut, incomplete BI (divided into two groups: anterolateral (AL) bundle intact or posteromedial (PM) bundle intact) and complete bicruciate tear. Data were collected using a Microscribe system at 0°, 30°, 60°, and 90° of knee flexion.

RESULTS

In comparison to the intact knees, incomplete BI and complete BI showed a significant increase of total antero-posterior tibial translation. The largest significant increase was observed at 90° of flexion after a complete bicruciate resection (p < 0.001). A threshold difference greater than 15 mm from the intact could be used to identify a complete BI from an incomplete BI evaluating the total antero-posterior translation at 90°. All sectioned states had significant increases compared with the intact condition in internal-external rotation and varus-valgus stability at all tested flexion angles.

CONCLUSION

Both incomplete and complete BI led to an important AP translation instability at all angles; however, full extension was the most stable position at all injured models. Total antero-posterior translation at 90° of knee flexion over 15 mm, in comparison to the intact condition, was indicative of a complete BI. Since the appropriate assessment of a combined ACL and PCL lesion remains a challenge, this study intends to assist its diagnosis. As BI's main antero-posterior instability occurred at 90°, a total antero-posterior drawer test is proposed to evaluate BI in the clinical setting. Total antero-posterior translation at 90° > 15 mm, in comparison to the intact condition or the contra-lateral non-injured knee, can be used to identify a complete from an incomplete BI.

Bicruciate lesion biomechanics, Part 2-treatment using a simultaneous tensioning protocol: ACL fixation first is better than PCL fixation first to restore tibiofemoral orientation

PURPOSE

An uncommon technique for bicruciate ligament reconstruction involving simultaneous tensioning of the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) grafts with ACL graft fixation first has been pointed out as superior to the "gold-standard" PCL graft fixation first. The purpose of this study was to compare tibiofemoral biomechanics between ACL fixation first and PCL fixation first in a simultaneous tensioning protocol for bicruciate ligament reconstruction.

METHODS

12 fresh-frozen cadaveric knees (six matched pairs) were tested using a custom testing system. Neutral tibial position representing tibiofemoral orientation, anterior-posterior (AP) tibial translation, varus-valgus laxity, and internal-external rotation were measured using a Microscribe 3DLX at 0°, 30°, 60°, and 90° of knee flexion. The following knee conditions were evaluated: intact, bicruciate deficient and following bicruciate reconstruction. A simultaneous tensioning protocol was used for bicruciate reconstruction and PCL fixation first was compared to ACL fixation first. PCL graft fixation was always performed at 90° of flexion and ACL graft fixation was always performed at full extension.

RESULTS

ACL fixation first achieved a tibiofemoral orientation closer to the intact knee than PCL fixation first at 90° flexion (1.8 ± 1.6 mm versus 6.1 ± 3.2 mm, p = 0.016). PCL fixation first had a larger decrease in AP translation than ACL fixation first at 30° flexion (64.6 ± 3.5% vs. 58.3 ± 2.4%, p = 0.01). No significant differences were found for varus/valgus, external-internal rotation decrements after bicruciate reconstruction nor for AP translation, varus/valgus and internal/external rotation increase after bicruciate lesion comparing ACL fixation first to PCL fixation first.

CONCLUSION

Bicruciate ligament reconstruction using a simultaneous tensioning protocol with ACL fixation first resulted in a closer to normal tibiofemoral orientation. This study will help guide surgeons in decision making for the graft tensioning protocol and fixation sequence in a bicruciate ligament reconstruction.

LEVEL OF EVIDENCE

V therapeutic study.

Allograft for knee ligament surgery: an American perspective

PURPOSE

Allografts are frequently use for ligamentous reconstruction at the knee. In the United States, tissue donation and distribution are highly regulated processes with thorough oversight from private and government entities. Allograft is widely available in the United States and allograft procurement is a large industry with varying procurement, sterilization, processing, and distribution procedures. It is important to understand allograft regulation and processing which may affect graft mechanical properties and biological graft integration.

METHODS

English-language literature, United States government and regulatory agency statues pertaining to allograft procurement, distribution, and usage were reviewed and the findings summarized.

RESULTS

During the processing of allograft, multiple factors including sterilization procedures, irradiation, storage conditions, and graft type all affect the biomechanical properties of the allograft tissue. Biological incorporation and ligamentization of allograft does occur, but at a slower rate compared with autograft. For ligamentous reconstruction around the knee, allograft offers shorter operative time, no donor-site morbidity, but has shown an increased risk for graft failure compared to autograft.

CONCLUSION

This article reviews the regulations on graft tissue within the United States, factors affecting the biomechanics of allograft tissue, differences in allograft tissue choices, and the use of allograft for anterior cruciate ligament reconstruction and multiligamentous knee injury reconstruction.

LEVEL OF EVIDENCE

V.

Satisfactory knee function after single-stage posterolateral corner reconstruction in the multi-ligament injured/dislocated knee using the anatomic single-graft technique

PURPOSE

Increasing importance has been placed on the posterolateral corner (PLC) in maintaining varus and rotational stability of the knee. The goal of this study was to evaluate knee function and clinical stability following a single-graft PLC reconstruction technique and identify factors associated with poor knee function.

METHODS

This study identified patients with a multi-ligament knee injury between 2006 and 2013. Patients who received a single-graft fibular collateral ligament and PLC reconstruction with a single-stage surgery during the study period and had a minimum follow-up of 2 years after surgery were included. Functional outcomes were assessed using Lysholm and IKDC scores. Varus and rotational knee laxity and range of motion were assessed using physical examination.

RESULTS

The final study cohort included 61 patients who underwent PLC reconstruction using a single-graft technique. The mean IKDC score was 74.1 (± 22.3) and the mean Lysholm score was 80.3 (± 21.8) at mean follow-up of 3.8 years (range 2-9 years). Mean range of motion at final follow-up measured from 0° to 126° [range flexion: 95-145, range extension: 0-5]. Fifty-eight patients (95%) had grade 0 varus laxity in full knee extension, and 54 patients (88.5%) had grade 0 varus laxity at 30° of knee flexion. Female gender was associated with a lower postoperative IKDC score (p = 0.04).

CONCLUSION

Surgical treatment of the PLC using a single-graft technique can result in satisfactory knee function and stable physical examination findings at minimum 2 years after surgery. Female gender was predictive of poor knee function after PLC reconstruction. Surgical treatment of PLC injuries should be individualized based on the timing of surgery, specific injured knee structures, and physical examination findings. This study helps validate the use of a single-graft technique for PLC reconstruction and can be used to help counsel patients about expected knee function after surgical treatment of PLC injuries. Level of evidence IV.

Return to duty following combat-related multi-ligamentous knee injury

INTRODUCTION

This retrospective cohort study characterized injury patterns, treatment practices, and identified the return to duty (RTD) rate following combat-related multi-ligament knee injuries (MLKI).

PATIENTS AND METHODS

We evaluated injury characteristics and treatment methods of 46 military service members who had sustained a MLKI during combat activity. The primary clinical outcome measure was ability to return to active military duty. Secondary outcomes included subjective pain score, knee motion, knee instability, and use of ambulatory assistive device.

RESULTS

The RTD rate was 41% (19/46). High-energy mechanism, neurovascular injury, compartment syndrome, traumatic knee arthrotomy, and intra-articular femur fracture (Orthopedic Trauma Association Classification (OTA) 33-B/C) were all more prevalent in subjects who were unable to return to duty (p<0.05). Acute external fixator application and poor knee range of motion (ROM) were also associated with military separation (p=0.041 and p=0.016, respectively). The most common ligament injury pattern (n=9; 20%) was combined disruption of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), posterolateral corner (PLC), and medial collateral ligament (MCL). However, number of ligaments injured was not associated with RTD status.

CONCLUSION

MLKIs sustained in a combat setting have a high incidence of associated lower extremity injuries. Certain associated injuries, such as intra-articular femur fracture, knee arthrotomy, neurovascular injury, and compartment syndrome may be more important than the severity of the knee ligamentous injury in determining RTD outcome.

Intra-articular peroneal nerve incarceration following multi-ligament knee injury

Knee dislocation with a common peroneal nerve injury is a serious problem. A case of multi-ligamentous knee injury with the unusual and interesting finding of a common peroneal nerve rupture incarcerated within the knee joint is presented. MRI and arthroscopic images are used to document this occurrence. To date, there are no published reports of a similar finding in the English orthopaedic literature. Level of evidence IV.

Traumatic Knee Dislocations: Evaluation, Management, and Surgical Treatment

Knee dislocations are catastrophic injuries that demand emergent evaluation and often require a multidisciplinary approach. Long-term outcome studies are relatively scarce secondary to the variability in any given study population and the wide variety of injury patterns between knee dislocations. Multiple controversies exist with regard to outcomes using various treatment methods (early vs late intervention, graft selection, repair vs reconstruction of medial and lateral structures, rehabilitation regimens). Careful clinical evaluation is essential when knee dislocation is suspected.