Palsy of the common peroneal nerve after traumatic dislocation of the knee

The known and unknown reality of knee dislocations: A systematic review

BACKGROUND

Knee dislocations (KD) are limb threatening injuries known to cause significant dysfunction and disability. This review aims to summarize KD knowledge and uncover areas where more research is needed.

METHODS

The published literature was queried according to PRISMA guidelines. Studies eligible for inclusion were clinical studies of knee dislocations. Studies published before 1990, or that focused on patellofemoral dislocation were excluded.

RESULTS

A total of 132 studies involving 43,869 knee dislocations were analyzed. The majority of patients were young adult males, with high-velocity trauma, particularly motor vehicle accidents, being the most common cause. Substance use and alcohol involvement were commonly reported. The predominant KD types were KD III (54.8 %) and KD IV (20.5 %). Meniscal tears were observed in over 50 % of cases, while cartilage injuries were present in 26.7 %. Neurovascular complications were significant, with popliteal artery injuries in 7.8 % and peroneal nerve injuries in 15.3 % of patients. Acute ligament repairs (64.2 %) were more common than delayed repairs (35.8 %), although the average time to repair was 56.1 days. Complications included amputations (2.3 %), fatalities (1.9 %), compartment syndrome (2.7 %), deep infection (5.3 %), and heterotopic ossification (21.6 %). Despite these severe injuries, a substantial loss to follow-up (19 %) and underreporting of functional outcomes were noted, limiting the comprehensive assessment of long-term recovery. A notable percentage of patients did not return to work or sports, with many requiring a change in profession due to their injuries, but these outcomes were only reported in 10 or fewer studies.

CONCLUSION

This study highlights the significant gaps in understanding the treatment strategies, financial burden, and long-term outcomes of knee dislocations. The incomplete data, particularly the high loss to follow-up rates and underreported functional outcomes, hinders the ability to make comprehensive assessments. Available results should thusly be interpreted with an understanding of the gaps in data, however return to sport and prior employment is often not achieved. Additionally, the potential influence of socioeconomic factors and substance abuse on treatment decisions and outcomes remains inadequately explored. Future research should focus on these areas to improve the management and prognosis of patients with knee dislocations, ensuring more accurate and thorough evaluations of long-term recovery and quality of life.

No effect of dislocation status at arrival in emergency department on outcome of knee joint dislocations

PURPOSE

Knee dislocation is a rare but severe injury of the lower extremities. The aim of this study was to report on the epidemiology, diagnostics and treatment of such injuries and to identify negative predictors of clinical outcomes.

METHODS

This retrospective analysis included all knee dislocations treated at a Level I Trauma Centre in Germany between 2009 and 2021. Medical records were categorised, collected and analysed in a standardised manner. A follow-up visit 1 year after the injury focused on limitations in knee mobility.

RESULTS

A total of 120 knee dislocations were included in the study. 29.3% of patients presented to the emergency department with a dislocated joint, and 17.5% (n = 21) had a neurovascular lesion. At follow-up 12 months after the injury, 65.8% of the patients reported limitations in the range of motion, and 11.7% (n = 14) reported severe limitations in daily activities. Site infections due to surgery occurred in 3.3% of patients. Increased body weight (r = 0.294; p < 0.001 and r = 0.259; p = 0.004), an increased body mass index above 25 kg/m2 (body mass index, r = 0.296; p < 0.001 and r = 0.264; p = 0.004) and deficits in peripheral perfusion as well as sensory and motor function (r = 0.231; p = 0.040 and r = -0.192; p = 0.036) were found to be negative predictive factors for clinical outcome. For posttraumatic neurovascular injury, lack of peripheral perfusion, insufficient sensory and motor function (r = -0.683; p < 0.0001), as well as a higher Schenck grade (r = 0.320; p = 0.037), were identified as independent risk factors. The status of dislocation at the site of the accident and on arrival at the emergency department had no impact on the outcome or neurovascular injury.

CONCLUSION

Knee dislocation is a rare injury with a high rate of severe complications such as neurovascular lesions. In particular, the initial status of neurovascular structures and injury classification showed a relevant negative correlation with the posttraumatic status of nerves and vessels. In particular, patients with these characteristics need close monitoring to prevent negative long-term consequences.

LEVEL OF EVIDENCE

Level III.

Stener-like lesion of the lateral meniscus in the setting of a multiligamentous knee injury: A case report

Traumatic dislocations of the knee can result in significant soft tissue damage including multiligamentous and meniscal knee injury. When a meniscal tear involves the posterior horn, the meniscus loses one of its attachments to the tibia and can become extruded from the joint. Stener-like lesions of the knee have been reported throughout the literature; however, they have been exclusively described as a distal tear of the medial collateral ligament (MCL) lying superficial to the pes anserine tendon which prevents anatomic healing. The purpose of this report is to present a previously unreported unique variant of a lateral meniscus tear in the setting of a MLKI. In this case presentation, the lateral meniscus became extruded superficial to the intact lateral collateral ligament (LCL) resulting in a Stener-like lesion. Corrective recognition of lesions like these and timely surgical intervention is recommended to restore native anatomy and prevent chronic pain, instability, and premature degenerative disease. Level IV, Case report.

Irreducible posterolateral knee dislocation: Diagnostic challenges and management (a surgical case report)

INTRODUCTION AND IMPORTANCE

Posterolateral knee dislocations are rare, complex injuries predominantly resulting from high-energy trauma. They present significant diagnostic and therapeutic challenges, crucial for maintaining long-term knee function and stability.

CASE PRESENTATION

We report the case of Mr. Y.G., a 34-year-old male who suffered a left knee posterolateral dislocation due to a motorcycle accident. Clinical examination and imaging revealed a valgus deformity, swelling, ecchymosis, and a persistent medial joint line groove. The injury was classified based on NEYRET et al. criteria and 2008 SOFCOT standards. Surgical intervention involved repairing medial structures and applying a femoro-tibial external fixator. Radiographic and MRI findings confirmed a complete capsuloligamentous rupture and chondral injury of the lateral condyle.

CLINICAL DISCUSSION

This case exemplifies the critical need for rapid radiological evaluation and tailored surgical interventions in managing posterolateral knee dislocations. It also demonstrates the effectiveness of using established classification systems for treatment planning and prognostic prediction.

CONCLUSION

Timely and suitable management is essential for successfully treating posterolateral knee dislocations. Utilizing recognized classification systems plays a key role in guiding management decisions and improving patient outcomes, ensuring optimal recovery and knee functionality.

Common peroneal nerve injury after tibial plateau fractures: A case series

Introduction

Common peroneal nerve (CPN) injury is a rare but significant complication of knee trauma. Given its low incidence, there is limited published evidence, but reports have shown dislocations and fractures associated with varus deformity are more likely to injure the nerve, causing foot drop. This study aims to document the incidence and outcome of CPN palsy in tibial plateau fractures (TPF).

Methods

We reviewed 746 cases of tibial plateau fractures treated between 2011 and 2020. We analysed patients' demographics, injury mechanisms, clinical course, and complications, and identified those with CPN palsies. Fractures were classified using the Schatzker, Luo and AO/OTA systems. The details of the CPN injury, including nerve conduction studies, duration of symptoms and outcome were recorded.

Results

We identified 11 patients who had concurrent TPFs and CPN palsies, an overall incidence of 1.47 %. Most fractures involved the medial column (n = 9), with the C3 fragmentary TPF pattern being the most common (n = 4). The incidence of CPN injury was higher in medial fractures (5 %) and bicondylar fractures (3 %). We also found that most patients (n = 9) recovered full neurological function within 2 years.

Discussion

This is the first study looking at a patient cohort sustaining concurrent TPFs and CPN injuries. It is a rare complication but should be looked for in high-risk medial and bicondylar fractures. We found that prognosis is better in TPF-associated CPN palsy than in other knee trauma, and that the majority of patients can expect a full recovery of nerve function.

Surgical management of peroneal nerve injuries

BACKGROUND

Traumatic peroneal nerve injuries are typically associated with high-energy injuries. The aim of this study was to evaluate the demographics and outcomes following surgical management of peroneal nerve injuries.

METHODS

Patients evaluated at a single institution with peroneal nerve injuries between 2001 and 2022 were retrospectively reviewed. Mechanism of injury, time to surgery, pre- and postoperative examinations, and operative reports were recorded. Satisfactory outcome, defined as the ability to achieve anti-gravity dorsiflexion strength or stronger following surgery, was compared between nerve grafting and nerve transfers in patients with at least 9 months of postoperative follow-up.

RESULTS

Thirty-seven patients had follow-up greater than 9 months after surgery, with an average follow-up of 3.8 years. Surgeries included neurolysis (n=5), direct repair (n=2), tibial motor nerve fascicle transfer to the anterior tibialis motor branch (n=18), or interposition nerve grafting using sural nerve autograft (n=12). At last follow-up, 59.5% (n=22) of patients had anti-gravity strength or stronger dorsiflexion. Nineteen (51.4%) patients used an ankle-foot orthosis during all or some activities. In patients that underwent nerve grafting only across the peroneal nerve defect, 44.4% (n=4) were able to achieve anti-gravity strength or stronger dorsiflexion. In patients that had a tibial nerve fascicle transfer to the tibialis anterior motor branch of the peroneal nerve, 42.9% (n=6) were able to achieve anti-gravity strength or stronger dorsiflexion at last follow-up. There was no statistical difference between nerve transfers and nerve grafting in postoperative dorsiflexion strength (p = 0.51).

CONCLUSION

Peroneal nerve injuries frequently occur in the setting of knee dislocations and similar high-energy injuries. Nerve surgery is not universally successful in restoration of ankle dorsiflexion, with one-third of patients requiring an ankle-foot orthosis at mid-term follow-up. Patients should be properly counseled on the treatment challenges and variable outcomes following peroneal nerve injuries.

Team Approach: Treatment of Traumatic Dislocations of the Knee

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Traumatic knee dislocations are complex injuries that can be associated with compromise of the neurovascular structures about the knee.

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Various classification systems for knee dislocations exist in the literature but should be used with caution as a prognostic tool because many knee dislocations fit into more than 1 category.

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Special populations of knee dislocations, such as obese patients and high-velocity mechanism injuries, require additional caution during the initial evaluation for possible vascular injuries.

Mid-Term Results following Traumatic Knee Joint Dislocation

PURPOSE

Although treatment strategies of knee joint dislocations have evolved, there is still no consensus on the best method and timing. New therapeutic concepts suggest that early one-stage treatment, including suturing and bracing of the cruciate ligaments in acute knee joint dislocation, are leading to improved functional results. This study aimed to evaluate the midterm functional outcome following traumatic knee joint dislocation and to determine whether the outcome is influenced by the surgical management, patient habitus or concomitant injuries.

METHODS

In this retrospective single center study, 38 patients with acute Schenck type II to IV knee dislocations were treated over an eight-year period in a level I trauma center. At follow-up, various clinical scores, such as the International Knee Documentation Committee (IKDC) Score, Lysholm Score, and Tegner Activity Scale (TAS), and individual questions about rehabilitation and activity levels of 38 patients were evaluated.

RESULTS

Mean follow-up was 5.5 ± 2.7 years. The mean IKDC Score was 65.6 ± 15.7 points, the average Lysholm Score was 70.5 ± 16.4 points and the median TAS was 4 (0-7), resulting in a loss of activity of 2 (range 0-6) points. There was no significant difference between a one-stage treatment compared to a two-stage approach. Ligament reconstruction of the ACL in a two-stage approach was required in only 33.3%. Further operations (early and late) were performed in 37% of cases. Being overweight was associated with more complications and worse outcomes, and external fixation with arthrofibrosis.

CONCLUSIONS

Knee dislocation is a severe trauma that often leads to a prolonged loss of function and increased knee pain over years, affecting the patient's activity. Clinical outcome is influenced significantly by concomitant injuries. Severe cases with initial external fixation are associated with a higher risk of knee stiffness and should be considered during rehabilitation. Obese patients present a challenge due to higher complication rates and lower postoperative knee function.

LEVEL OF EVIDENCE

Retrospective single center study, level III.

Relationship Between Peroneal Nerve and Anterior Cruciate Ligament Involvement in Multiligamentous Knee Injury: A Multicenter Study

INTRODUCTION

Peroneal nerve injuries are rare injuries and usually associated with multiligamentous knee injuries (MLKIs) involving one or both cruciate ligaments. The purpose of our study was to perform a multicenter retrospective cohort analysis to examine the rates of peroneal nerve injuries and to see whether a peroneal nerve injury was suggestive of a particular injury pattern.

METHODS

A retrospective chart review was conducted in patients who were diagnosed with MLKI at two level I trauma centers from January 2001 to March 2021. MLKIs were defined as complete injuries to two or more knee ligaments that required surgical reconstruction or repair. Peroneal nerve injury was clinically diagnosed in these patients by the attending orthopaedic surgeon. Radiographs, advanced imaging, and surgical characteristics were obtained through a chart review.

RESULTS

Overall, 221 patients were included in this study. The mean age was 35.9 years, and 72.9% of the population was male. Overall, the incidence of clinical peroneal nerve injury was 19.5% (43 patients). One hundred percent of the patients with peroneal nerve injury had a posterolateral corner injury. Among patients with peroneal nerve injury, 95.3% had a complete anterior cruciate ligament (ACL) rupture as compared with 4.7% of the patients who presented with an intact ACL. There was 4.4 times of greater relative risk of peroneal nerve injury in the MLKI with ACL tear group compared with the MLKI without an ACL tear group. No statistical difference was observed in age, sex, or body mass index between patients experiencing peroneal nerve injuries and those who did not.

CONCLUSION

The rate of ACL involvement in patients presenting with a traumatic peroneal nerve palsy is exceptionally high, whereas the chance of having a spared ACL is exceptionally low. More than 90% of the patients presenting with a nerve palsy will have sustained, at the least, an ACL and posterolateral corner injury.

LEVEL OF EVIDENCE

IV, Case Series.

Predictors of Mid- to Long-Term Outcomes in Patients Experiencing a Knee Dislocation: A Systematic Review of Clinical Studies

Knee dislocations (KDs) are devastating injuries for patients and present complex challenges for orthopaedic surgeons. Although short-term outcomes have been studied, there are few long-term outcomes of these injuries available in the literature. The purpose of this study is to determine factors that influence mid- to long-term clinical outcomes following surgical treatment of KD. A review of the current literature was performed by searching PubMed, the Cochrane Library, and Embase to identify clinical studies published from 2010 to 2019 with a minimum 2-year follow-up that reported outcomes following surgical treatment of KDs. Ten studies (6 level III, 4 level IV) were included. At mid- (2-10 y) to long-term (>10 y) follow-up, concomitant arterial, cartilage, and combined meniscus damage were predictive factors for inferior Lysholm and International Knee Documentation Committee (IKDC) scores when compared with patients without these associated injuries. Although concomitant neurological damage may influence short-term outcomes due to decreased mobility, at longer follow-up periods it does not appear to predict worse clinical outcomes when compared with patients without concomitant neurological injury. Frank and polytrauma KDs have been associated with worse mid- to long-term outcomes when compared with transient and isolated KDs. Patients who underwent surgery within 6 weeks of trauma experienced better long-term outcomes than those who underwent surgery longer than 6 weeks after the initial injury. However, the small sample size of this study makes it difficult to make valid recommendations. Lastly, female sex, patients older than 30 years at the time of injury and a body mass index (BMI) greater than 35 kg/m² are factors that have been associated with worse mid- to long-term Lysholm and IKDC scores. The results of this review suggest that female sex, age >30 years, BMI >35 kg/m², concomitant cartilage damage, combined medial and lateral meniscal damage, KDs that do not spontaneously relocate, and KDs associated with polytrauma may predict worse results at mid- to long-term follow-up.

Predictors Using Machine Learning of Complete Peroneal Nerve Palsy Recovery After Multiligamentous Knee Injury: A Multicenter Retrospective Cohort Study

Background

Peroneal nerve (PN) palsy is one of the most debilitating sequelae of multiligamentous knee injuries (MLKIs). There is limited research on recovery from complete PN palsy.

Purpose/Hypothesis

The purpose of this study was to characterize PN injuries and develop a predictive model of complete PN recovery after MLKI using machine learning. It was hypothesized that elevated body mass index (BMI) would be predictive of lower likelihood of recovery.

Study Design

Case-control study; Level of evidence, 3.

Methods

The authors conducted a retrospective review of patients seen at 2 urban hospital systems for treatment of MLKI with associated complete PN palsy, defined as the presence of complete foot drop with or without sensory deficits on physical examination. Recovery was defined as the complete resolution of foot drop. A random forest (RF) classifier algorithm was used to identify demographic, injury, treatment, and postoperative variables that were significant predictors of recovery from complete PN palsy. Validity of the RF model was assessed using overall accuracy, F1 score, and area under the receiver operating characteristic curve (AUC).

Results

Overall, 16 patients with MLKI with associated complete PN palsy were included in the cohort. Among them, 75% (12/16) had documented knee dislocation requiring reduction. Complete recovery occurred in 4 patients (25%). Nerve contusions on magnetic resonance imaging were more common among patients without PN recovery, but there were no other significant differences between recovery and nonrecovery groups. The RF model found that older age, increasing BMI, and male sex were predictive of worse likelihood of PN recovery. The model was found to have good validity, with a classification accuracy of 75%, F1 score of 0.86, and AUC of 0.64.

Conclusion

The RF model in this study found that increasing age, BMI, and male sex were predictive of decreased likelihood of nerve recovery. While further study of machine learning models with larger patient data sets is required to identify the most superior model, these findings present an opportunity for orthopaedic surgeons to better identify, counsel, and treat patients with MLKIs and concomitant complete PN palsy.

Clinical, functional, and patient-reported outcome of traumatic knee dislocations: a retrospective cohort study of 75 patients with 6.5-year follow-up

INTRODUCTION

At present, limited knowledge regarding clinical, functional, and patient-reported outcomes at mid- and long-terms after surgical treatment of traumatic knee dislocations is available. This study aimed to investigate the mid-term recovery regarding clinical, functional, and patient-reported outcomes in patients following knee dislocation with associated multi-ligament injuries.

MATERIALS AND METHODS

The study design was a cross-sectional cohort study. Data were collected by retrospective chart review, clinical examination, and interview of patients. All patients treated surgically following a knee dislocation between January 2000 and December 2011 were included. The surgical technique was up to the decision of the individual surgeon. The main outcome was the Lysholm knee score. Secondary outcomes consist of clinical knee examination, functional performance test, pain, and patient-reported outcome across several domains in function, sport, pain, and quality of life.

RESULTS

Seventy-five patients (66.3%) accepted the invitation to participate. The mean age at the time of knee dislocation was 33.5 years, with a range of 16-65 years of age. The mean follow-up time was 78 months (R: 17-147). 75% of patient a Schenck's type 1 lesion and 23% a type 3. The median Lysholm knee score was 83 (R: 18-100). The mean KOOS for the five subscales were pain 84.5 (95% CI 80.5-88.5), symptoms 75.1 (95% CI 70.7-79.4), ADL 87.0 (95% CI 83.1-90.9), sport 59.9 (95% CI 53.3-66.4), and QOL 71.3 (95% CI 67.0-75.6). The mean Tegner activity level was 5.1 (95% CI 4.5-5.7). The median single assessment numeric evaluation (SANE) was 93 (R: 0-100). The pain intensity score for pain (VAS) during activity was reported with a mean of 2.7 (95% CI 2.1-3.3). The objective IKDC examination showed 76% of patients grouped by Grade A (normal knee function) or Grade B (nearly normal).

CONCLUSION

With a mean follow-up of 6.5 years, combined repair and reconstruction surgery following a knee dislocation shows good to excellent patient-reported outcome and more than 75% of patients experiencing normal knee functioned evaluated by the IKDC score.

Examining the Bone Bruise Patterns in Multiligament Knee Injuries With Peroneal Nerve Injury

BACKGROUND

Tibiofemoral bone bruise patterns seen on magnetic resonance imaging (MRI) are associated with ligamentous injuries in the acutely injured knee. Bone bruise patterns in multiligament knee injuries (MLKIs) and particularly their association with common peroneal nerve (CPN) injuries are not well described.

PURPOSE

To analyze the tibiofemoral bone bruise patterns in MLKIs with and without peroneal nerve injury.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We retrospectively identified 123 patients treated for an acute MLKI at a level 1 trauma center between January 2001 and March 2021. Patients were grouped into injury subtypes using the Schenck classification. Within this cohort, patients with clinically documented complete (motor and sensory loss) and/or partial CPN palsies on physical examination were identified. Imaging criteria required an MRI scan on a 1.5 or 3 Tesla scanner within 30 days of the initial MLKI. Images were retrospectively interpreted for bone bruising patterns by 2 board-certified musculoskeletal radiologists. The location of the bone bruises was mapped on fat-suppressed T2-weighted coronal and sagittal images. Bruise patterns were compared among patients with and without CPN injury.

RESULTS

Of the 108 patients with a MLKI who met the a priori inclusion criteria, 26 (24.1%) were found to have a CPN injury (N = 20 complete; N = 6 partial) on physical examination. For CPN-injured patients, the most common mechanism of injury was high-energy trauma (N = 19 [73%]). The presence of a grade 3 posterolateral corner (PLC) injury (N = 25; odds ratio [OR], 23.81 [95% CI, 3.08-184.1]; P = .0024), anteromedial femoral condyle bone bruising (N = 24; OR, 21.9 [95% CI, 3.40-202.9]; P < .001), or a documented knee dislocation (N = 16; OR, 3.45 [95% CI, 1.38-8.62]; P = .007) was significantly associated with the presence of a CPN injury. Of the 26 patients with CPN injury, 24 (92.3%) had at least 1 anteromedial femoral condyle bone bruise. All 20 (100%) patients with complete CPN injury also had at least 1 anteromedial femoral condyle bone bruise on MRI. In our MLKI cohort, the presence of anteromedial femoral condyle bone bruising had a sensitivity of 92.3% and a specificity of 64.6% for the presence of CPN injury on physical examination.

CONCLUSION

In our MLKI cohort, the presence of a grade 3 PLC injury had the greatest association with CPN injury. Additionally, anteromedial femoral condyle bone bruising on MRI was a highly sensitive finding that was significantly correlated with CPN injury on physical examination. The high prevalence of grade 3 PLC injuries and anteromedial tibiofemoral bone bruising suggests that these MLKIs with CPN injuries most commonly occurred from a hyperextension-varus mechanism caused by a high-energy blow to the anteromedial knee.

Minimally Invasive Surgical Approach for Open Common Peroneal Nerve Neurolysis in the Setting of Previous Posterior Schwannoma Removal

The common peroneal nerve (CPN) runs laterally around the fibular neck and enters the peroneal tunnel, where it divides into the deep, superficial, and recurrent peroneal nerves. CPN entrapment is the most common neuropathy of the lower extremity and is vulnerable at the fibular neck because of its superficial location. Schwannomas are benign, encapsulated tumors of the nerve sheath that can occur sporadically or in cases of neurocutaneous conditions, such neurofibromatosis type 2. In cases with compressive neuropathy resulting in significant or progressive motor loss, decompression and neurolysis should be attempted. We present a technical note for the treatment of CPN compressive neuropathy in the setting of a previous ipsilateral schwannoma removal with a minimally invasive surgical approach and neurolysis of the CPN at the fibular neck.

Medical management and rehabilitation in posttraumatic common peroneal nerve palsy

Introduction. The common peroneal nerve and the tibial nerve are the two major components into which the sciatic nerve divides. The severity of common peroneal nerve damage depends on the aetiopathogenic mechanism and the place of injury. The peroneal ram of the sciatic nerve injury is the most common cause of mononeuropathy of the lower limb which can cause a signi-ficant disability if is not properly diagnosed and treated. Material and method. We present the case of a 40-year-old patient who suffered a polytrauma by road accident resulting in left tro-chanteric-diaphyseal femoral comminuted open fracture, lacerated wound on the posterolateral middle third of the left thigh, left sacral wing fracture without displacement, left L1, L2, L3 tran-sverse apophyseal fractures and splenic laceration, treated surgically and orthopedically. The pa-tient was admitted to the Medical Reabilitation Department of Sibiu for left leg motor deficit, mechanical pain and functional deficit of the left hip and ankle, gait disorders. Complex rehabi-litation treatment was initiated 3 months after the accident. Results and discussion. Common pe-roneal nerve palsy was confirmed following neurological consultation the day after admission to Orthopaedics-Traumatology Department of Sibiu where continuous extension-traction was performed in order to relax the fracture and subsequent osteosynthesis surgery of the femur fracture. The presence of a deep and lacerating wound on the posterolateral left thigh caused the nerve injury. The coagulase-negative Staphylococcus aureus overinfection of the wound required secondary suturing and subsequently led to fibrous scar formation, adversely affecting the post-injury repair of the common fibular nerve. Conclusions. In patients with posttraumatic common peroneal nerve palsy, early diagnosis and appropriate treatment, including medical rehabilitation, are essential. Medical rehabilitation should be continued on a sustained basis be-cause nerve regeneration occurs slowly. The prognosis mainly depends on the severity of the initial nerve injury. Keywords: common fibular nerve injury, polytrauma, medical rehabilitation

Demographic analysis of knee dislocation: A rare mechanism of injury

PURPOSE

The aim of this study was to present to the literature a rare injury mechanism that causes knee dislocation (KD) and describe its characteristics.

METHODS

A retrospective review of patients with KD who were treated between January 2014 and December 2019 at our hospital was performed. Patients with KD due to rotavator machine injury were included in Group 1 and all patients with KD due to other etiological reasons were included in Group 2. Patients' age, gender, side, injury mechanism, time to surgery, length of stay (LOS), operation time, follow-up time, neurological injury status, vascular injury status, open injury status, and surgical interventions were evaluated.

RESULTS

A total of 34 patients were evaluated in the study. There was no statistically significant difference between the groups in terms of age, gender, side, or follow-up time (p = .915, p = 1.000, p = .682, p = .374, respectively). However, LOS and time to surgery were statistically significantly longer in Group 1 (p = .037, p = .010, respectively). Moreover, neurovascular damage was statistically significantly more common in Group 1.

CONCLUSION

As a rare injury mechanism for KD, rotavator machine injuries cause more neurovascular injuries in patients compared to other injury mechanisms and increase the time to surgery and LOS due to preoperative soft tissue damage.

Traumatic Peroneal Nerve Injuries: A Systematic Review

BACKGROUND

The common peroneal nerve (CPN) is the most commonly injured peripheral nerve of the lower extremity in patients with trauma. Traumatic CPN injuries have historically been associated with relatively poor outcomes and patient satisfaction, although improved surgical technique and novel procedures appear to improve outcomes. Given the variety of underlying injury modalities, treatment options, and prognostic variables, we sought to evaluate and summarize the current literature on traumatic CPN injuries and to provide recommendations from an analysis of the included studies for treatment and future research.

METHODS

A systematic review was performed using PubMed, Embase, and Cochrane databases per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Search terms consisted of variations of "peroneal nerve" or "fibular nerve" combined with "injury," "laceration," "entrapment," "repair," or "neurolysis." Information with regard to treatment modality, outcomes, and patient demographic characteristics was recorded and analyzed.

RESULTS

The initial search yielded 2,301 articles; 42 met eligibility criteria. Factors associated with better outcomes included a shorter preoperative interval, shorter graft length when an interposed graft was used, nerve continuity, and younger patient age. Gender or sex was not mentioned as a factor affecting outcomes in any study. Motor grades of ≥M3 on the British Medical Research Council (MRC) scale are typically considered successful outcomes. This was achieved in 81.4% of patients who underwent neurolysis, 78.8% of patients who underwent end-to-end suturing, 49.0% of patients who underwent nerve grafting, 62.9% of patients who underwent nerve transfer, 81.5% of patients who underwent isolated posterior tibial tendon transfer (PTTT), and 84.2% of patients who underwent a surgical procedure with concurrent PTTT.

CONCLUSIONS

Studies included in this review were heterogenous, complicating our ability to perform further analysis. It is not possible to uniformly advocate for the best treatment option, given diverse injury modalities and patient presentations and a variety of prognostic factors. Many studies do not show outcomes with respect to injury modality. Future studies should show preoperative muscle strengths and should clearly define outcomes based on the injury modality and surgical treatment option. This would allow for greater analysis of the most appropriate treatment option for a given mechanism of injury. Newer surgical techniques are promising and should be further explored.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Distal posterolateral corner injury in the setting of multiligament knee injury increases risk of common peroneal palsy

PURPOSE

The purpose of this study was to identify if the location of posterolateral corner (PLC) injury was predictive of clinical common peroneal nerve (CPN) palsy.

METHODS

A retrospective chart review was conducted of patients presenting to our institution with operative PLC injuries. Assessment of concomitant injuries and presence of neurologic injury was completed via chart review and magnetic resonance imaging (MRI) review. A fellowship-trained musculoskeletal radiologist reviewed the PLC injury and categorized it into distal, middle and proximal injuries with or without a biceps femoral avulsion. The CPN was evaluated for signs of displacement or neuritis.

RESULTS

Forty-seven operatively managed patients between 2014 and 2019 (mean age-at-injury 29.5 ± 10.7 years) were included in this study. Eleven (23.4%) total patients presented with a clinical CPN palsy. Distal PLC injuries were significantly associated with CPN palsy [9 (81.8%) patients, (P = 0.041)]. Nine of 11 (81.8%) patients with CPN palsy had biceps femoral avulsion (P = 0.041). Of the patients presenting with CPN palsy, only four (36.4%) patients experienced complete neurologic recovery. Three of 7 patients (43%) with an intact CPN had full resolution of their clinically complete CPN palsy at the time of follow-up (482 ± 357 days). All patients presenting with a CPN palsy also had a complete anterior cruciate ligament (ACL) rupture in addition to a PLC injury (P = 0.009), with or without a posterior cruciate ligament (PCL) injury. No patient presenting with an isolated pattern of PCL-PLC injury (those without ACL tears) had a clinical CPN palsy.

CONCLUSION

Distal PLC injuries have a strong association with clinical CPN palsy, with suboptimal resolution in the initial post-operative period. Specifically, the presence of a biceps femoris avulsion injury was highly associated with a clinical CPN palsy. Additionally, CPN palsy in the context of PLC injury has a strong association with concomitant ACL injury. Furthermore, the relative rates of involvement of the ACL vs. PCL suggest that specific injury mechanism may have an important role in CPN palsy.

LEVEL OF EVIDENCE

IV.

Postoperative Rehabilitation and Return to Sport Following Multiligament Knee Reconstruction

Multiligament knee injuries (MLKIs) are debilitating injuries that increasingly occur in young athletes. Return to sport (RTS) has historically been considered unlikely due to the severity of these injuries. Reporting in the literature regarding objective outcomes following MLKI, including RTS, is lacking, as are clear protocols for both rehabilitation progressions and RTS testing. RTS following MLKI is a complex process that requires an extended recovery duration compared to other surgery types. Progressions through postoperative rehabilitation and RTS should be thoughtful, gradual, and criterion based. After effective anatomic reconstruction to restore joint stability, objective measures of recovery including range of motion, strength, movement quality, power, and overall conditioning guide decision-making throughout the recovery process. It is important to frame the recovery process of the athlete in the context of the severity of their injury, as it is typically slower and less linear. Improved reporting on objective outcomes will enhance our understanding of recovery expectations within this population by highlighting persistent deficits that may interfere with a full recovery, including RTS.

A Comparative Study of Clinical Outcomes and Functional Status after Knee Fracture and Knee Fracture Dislocation

The aim of this study was to compare outcomes of tibial plateau fracture dislocations (FD) with tibial plateau fractures alone. This study was an analysis of a series of tibial plateau fractures, in which FD was defined as a fracture of the tibial plateau with an associated loss of congruent joint reduction and stability of the knee, and classified by the Moore system. Patient data collected included demographics, injury information, and functional outcomes (short musculoskeletal function assessment [SMFA] score and Pain by the visual analog scale). Clinical outcomes at follow-up were recorded including knee range of motion, knee stability and development of complications. There were a total of 325 tibial plateau fracture patients treated operatively, of which 22.2% were identified as FD (n = 72). At injury presentation there was no difference with regard to nerve injury or compartment syndrome (both p > 0.05). FD patients had a higher incidence of arterial injury and acute ligament repair (both p < 0.005). At a mean follow-up of 17.5 months, FD patients were similar with regard to pain, total SMFA scores, and return to sports than their non-FD counterparts (p = 0.884, p = 0.531, p = 0.802). FD patients were found to have decreased knee flexion compared with non-FD patients by 5 degrees (mean: 120 and 125 degrees) (p < 0.05). FD patients also had a higher incidence of late knee instability and subsequent surgery for ligament reconstruction (p < 0.005 & p < 0.05). However, there was no difference in neurological function between groups at follow-up (p = 0.102). Despite the higher incidence of ligamentous instability and decreased range of motion, FD patients appear to have similar long-term functional outcomes compared with non-FD of the tibial plateau. While FD patients initially presented with a higher incidence of arterial injury, neurovascular outcomes at final follow-up were similar to those without a dislocation.

Knee joint dislocation: overview and current concepts

Knee joint dislocation is a relatively uncommon injury but its management is important because of the associated high risk of vascular, neurological and multi-ligamentous knee injuries. Clinicians must be aware that not all knee dislocations are diagnosed on plain X-rays; a high index of suspicion is required based on clinical evaluation. Multidisciplinary specialist care is required in all cases to achieve best outcomes. Early one-stage or multiple staged ligament repair and reconstruction offer better outcomes, but most patients have some long-term functional limitation. This article provides insights into the epidemiology and management of this injury and its devastating effects.

On-field Emergencies and Emergency Action Plans

Sideline coverage can be an enjoyable experience and provide the opportunity to witness and evaluate an athlete's pathology at the time of injury. While the majority of on-field injury will likely be of low acuity, it is essential to develop an Emergency Action Plan (EAP) to deliver excellent medical care efficiently. The EAP should provide a written, standardized multidisciplinary approach involving key personnel. The EAP should be rehearsed on at least an annual basis and should highlight the initial assessment of the patient while also accounting for the various types of trauma that may occur on the field and appropriate field extrication procedures. As most players who have a true on-field emergency will not return to same-day play, a thorough understanding of how to deliver emergency care and transfer the player to a higher level of care is essential.

The Impact of the Ligamentous Injury Pattern and Associated Neurovascular Injury on Ultimate Knee Function in Patients with Traumatic Knee Dislocations

The present study aims to investigate whether there is a relationship between the ligamentous injury pattern and concomitant neurovascular injury with long-term functional outcomes in patients with traumatic knee dislocations (TKDs). A total of 42 patients with TKDs were categorized according to the Schenck's classification based on the pattern of ligamentous injury. Concomitant vascular and neural injuries were recorded. Long-term functional outcomes were assessed using several objective and subjective outcome measures. This retrospective study was conducted in two phases: (1) to analyze the impact of ligamentous injury pattern on functional outcomes of patients with TKDs in the overall study population, by comparing all the variables among Schenck's grades; (2) to determine the impact of concomitant vascular and neural injury on ultimate knee function based on the subgroup analyses. In the overall study statistical differences were determined among each pattern of ligamentous injury in the total range of motion (ROM) and scoring systems (chi-squared test, p = 0.254). The overall rates of vascular and neural injury were 26 and 28%, respectively. In subgroup analyses, 40 patients were divided into three subgroups: group A (isolated concomitant neural injury), group B (isolated concomitant vascular injury), group C (without concomitant major vascular or neural injury). The analysis revealed a significant difference in the total ROM (p = 0.005), flexion measurements (p = 0.004), and the loss of extension (p = 0.003). Group A had the lowest total knee ROM and the mean flexion degrees, as well as the highest loss of extension. Concerning functional scoring systems including the combined Knee Society Score (knee score + function score), Lysholm knee scoring scale, and International Knee Documentation Committee score, subgroup analyses revealed significant differences among the groups (p = 0.001, p < 0.01 for all scores). All the scores were found to be lowest in group A. Evidence from the current study showed that the ligamentous pattern and concomitant neurovascular injury both may have a significant impact on ultimate knee function in patients with TKDs. This is a Level III-retrospective comparative study.

Treatment approach to isolated common peroneal nerve palsy by mechanism of injury: Systematic review and meta-analysis of individual participants' data

BACKGROUND

We reviewed the individual participant data of patients who sustained isolated common peroneal nerve (CPN) injuries resulting in foot drop. Functional results were compared between eight interventions for CPN palsies to determine step-wise treatment approaches for the underlying mechanisms of nerve injury.

METHODS

PubMed, Embase, Cochrane Library, Web of Science, Scopus, and CINAHL databases were searched. PRISMA-IPD and Cochrane guidelines were followed in the data search. Eligible patients sustained isolated CPN injuries resulting in their foot drop. Patients were stratified by mechanisms of nerve injury, ages, duration of motor symptoms, and nerve defect/zone of injury sizes, and were compared by functional results (poor = 0, fair = 1, good = 2, excellent = 3), using meta-regression between interventions. Interventions evaluated were primary neurorrhaphy, neurolysis, nerve grafts, partial nerve transfer, neuromusculotendinous transfer, tendon transfer, ankle-foot orthosis (AFO), and arthrodesis.

RESULTS

One hundred and forty-four studies included 1284 patients published from 1985 through 2020. Transection/Cut: Excellent functional results following tendon transfer (OR: 126, 95%CI: 6.9, 2279.7, p=0.001), compared to AFO. Rupture/Avulsion: Excellent functional results following tendon transfer (OR: 73985359, 95%CI: 73985359, 73985359, p<0.001), nerve graft (OR: 4465917, 95%CI: 1288542, 15478276, p<0.001), and neuromusculotendinous transfer (OR: 42277348, 95%CI: 3001397, 595514030, p<0.001), compared to AFO. Traction/Stretch: Good functional results following tendon transfer (OR: 4.1, 95%CI: 1.17, 14.38, p=0.028), compared to AFO. Entrapment: Excellent functional results following neurolysis (OR: 4.6, 95%CI: 1.3, 16.6, p=0.019), compared to AFO.

CONCLUSIONS

Functional results may be optimized for treatments by the mechanism of nerve injury. Transection/Cut and Traction/Stretch had the best functional results following tendon transfer. Rupture/Avulsion had the best functional results following tendon transfer, nerve graft, or neuromusculotendinous transfer. Entrapment had the best functional results following neurolysis.

Acute Versus Delayed Surgical Intervention in Multiligament Knee Injuries: A Systematic Review

Background:

The optimal timing of surgical intervention for multiligament knee injuries remains controversial.

Purpose:

To review the clinical and functional outcomes after acute and delayed surgical intervention for multiligament knee injuries.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

We performed a search of the PubMed, Embase, Cochrane Library, and Web of Science databases from inception to September 2020. Eligible studies reported on knee dislocations, multiligament knee injuries, or bicruciate ligament injuries in adult patients (age, ≥18 years). In addition to comparing outcomes between acute and delayed surgical intervention groups, we conducted 3 subgroup analyses for outcomes within isolated knee injuries, knee injuries with concomitant polytrauma/fractures, and high-level (level 2) studies.

Results:

Included in the analysis were 31 studies, designated as evidence level 2 (n = 3), level 3 (n = 8), and level 4 (n = 20). These studies reported on 2594 multiligament knee injuries sustained by 2585 patients (mean age, 25.1-65.3 years; mean follow-up, 12-157.2 months). At the latest follow-up timepoint, the mean Lysholm (n = 375), International Knee Documentation Committee (IKDC) (n = 286), and Tegner (n = 129) scores for the acute surgical intervention group were 73.60, 67.61, and 5.06, respectively. For the delayed surgical intervention group, the mean Lysholm (n = 196), IKDC (n = 172), and Tegner (n = 74) scores were 85.23, 72.32, and 4.85, respectively. The mean Lysholm (n = 323), IKDC (n = 236), and Tegner (n = 143) scores for our isolated subgroup were 83.7, 74.8, and 5.0, respectively. By comparison, the mean Lysholm (n = 270), IKDC (n = 236), and Tegner (n = 206) scores for the polytrauma/fractures subgroup were 83.3, 64.5, and 5.0, respectively.

Conclusion:

The results of our systematic review did not elucidate whether acute or delayed surgical intervention produced superior clinical and functional outcomes. Although previous evidence has supported acute surgical intervention, future prospective randomized controlled trials and matched cohort studies must be completed to confirm these findings.

Magnetic resonance imaging evaluation of common peroneal nerve injury in acute and subacute posterolateral corner lesion: a retrospective study

Objective

To evaluate qualitative and quantitative magnetic resonance imaging (MRI) criteria for injury of the common peroneal nerve (CPN) in patients with acute or subacute injuries in the posterolateral corner (PLC) of the knee, as well as to evaluate the reproducibility of MRI evaluation of CPN alterations.

Materials and Methods

This was a retrospective study of 38 consecutive patients submitted to MRI and diagnosed with acute or subacute injury to the PLC of the knee (patient group) and 38 patients with normal MRI results (control group). Two musculoskeletal radiologists (designated radiologist A and radiologist B, respectively) evaluated the images. Nerve injury was classified as neurapraxia, axonotmesis, or neurotmesis. Signal strength was measured at the CPN, the tibial nerve (TN), and a superficial vein (SV). The CPN/TN and CPN/SV signal ratios were calculated. The status of each PLC structure, including the popliteal tendon, arcuate ligament, lateral collateral ligament, and biceps tendon, was classified as normal, partially torn, or completely torn, as was that of the cruciate ligaments. For the semiquantitative analysis of interobserver agreement, the kappa statistic was calculated, whereas a receiver operating characteristic (ROC) curve was used for the quantitative analysis.

Results

In the patient group, radiologist A found CPN abnormalities in 15 cases (39.4%)-neurapraxia in eight and axonotmesis in seven-whereas radiologist B found CPN abnormalities in 14 (36.8%)-neurapraxia in nine and axonotmesis in five. The kappa statistic showed excellent interobserver agreement. In the control group, the CPN/TN signal ratio ranged from 0.63 to 1.1 and the CPN/SV signal ratio ranged from 0.16 to 0.41, compared with 1.30-4.02 and 0.27-1.08, respectively, in the patient group. The ROC curve analysis demonstrated that the CPN/TN signal ratio at a cutoff value of 1.39 had high (93.3%) specificity for the identification of nerve damage, compared with 81.3% for the CPN/SV signal ratio at a cutoff value of 0.41.

Conclusion

CPN alterations are common in patients with PLC injury detected on MRI, and the level of interobserver agreement for such alterations was excellent. Calculating the CPN/TN and CPN/SV signal ratios may increase diagnostic confidence. We recommend systematic analysis of the CPN in cases of PLC injury.

Determining the real site of peroneal nerve injury with knee dislocation: Earlierier is easier

Common peroneal nerve (CPN) injury is a recognised complication of traumatic knee dislocation with a direct association between the degree of ligamentous injury and the degree of CPN injury. It is essential explore and repair these injuries in good time to reduce morbidity. Often exploration only involves the portion of this nerve associated with the joint as it courses around the fibular head. However, a recent case highlighted the importance of proximal exploration to its branching point from the sciatic nerve, a known point of fragility, even if other defects have been identified.

Increased Neurovascular Morbidity Is Seen in Documented Knee Dislocation Versus Multiligamentous Knee Injury

This article was updated on May 19, 2021 because of previous errors, which were discovered after the preliminary version of the article was posted online. In the legend for Figure 3-A, the phrase that had read "T1-weighted coronal MRI showing a right knee" now reads "T1-weighted coronal MRI showing a left knee." On page 924, in the section entitled "Materials and Methods," the sentence that had read "If there was no radiographic evidence or if there was a clinical note that documented visible deformity around the knee with no reduction maneuver being performed, then the patient was classified into the non-dislocated MLKI group." now reads "If there was no radiographic evidence or if there was no clinical note that documented visible deformity around the knee with no reduction maneuver being performed, then the patient was classified into the non-dislocated MLKI group." On page 925, in the section entitled "Analysis," the sentence that had read "Our study included 78 dislocated MLKIs and non-dislocated MLKIs, so both cohorts were adequately powered for the overall analysis." now reads "Our study included 45 dislocated MLKIs and 78 non-dislocated MLKIs, so both cohorts were adequately powered for the overall analysis." Finally, on page 927, in the section entitled "Discussion," the sentence that had read "Interestingly, we found that MLKIs with a documented knee dislocation had a substantially higher rate of vascular injury (23%) compared with those without (3%)." now reads "Interestingly, we found that MLKIs with a documented knee dislocation had a substantially higher rate of vascular injury (18%) compared with those without (4%)."

Current Concepts Review: Common Peroneal Nerve Palsy After Knee Dislocations

Dislocation of the native knee represents a challenging injury, further complicated by the high rate of concurrent injury to the common peroneal nerve (CPN). Initial management of this injury requires a thorough neurovascular examination, given the prevalence of popliteal artery injury and limb-threatening ischemia. Further management of a knee dislocation with associated CPN palsy requires coordinated care involving the sports surgeon for ligamentous knee reconstruction and the peripheral nerve surgeon for staged or concurrent peroneal nerve decompression and/or reconstruction. Finally, the foot and ankle surgeon is often required to manage a foot drop with a distal tendon transfer to restore foot dorsiflexion. For instance, the Bridle Procedure-a modification of the anterior transfer of the posterior tibialis muscle, under the extensor retinaculum, with tri-tendon anastomosis to the anterior tibial and peroneus longus tendons at the anterior ankle-can successfully return patients to brace-free ambulation and athletic function following CPN palsy. Cross-discipline coordination and collaboration is essential to ensure appropriate timing of operative interventions and ensure maintenance of passive dorsiflexion prior to tendon transfer.

Impacts of Rehabilitation Gait Training on Functional Outcomes after Tibial Nerve Transfer for Patients with Peroneal Nerve Injury: A Nonrandomized Controlled Trial

BACKGROUND

Although there was initial success using tibial nerve transfer to restore ankle dorsiflexion following peroneal nerve injury, results from later series were less promising. A potential reason is coactivation of the much stronger antagonistic muscles during gait. The purpose of this study was to test the hypothesis that gait training would improve functional performance following tibial nerve transfer.

METHODS

Using a prospective, nonrandomized, controlled study design, patients were divided into two groups: surgery only or surgery plus gait training. Of the 20 patients who showed reinnervation in the tibialis anterior muscle, 10 were assigned to the gait training group, and an equal number were in the control group. Those in the treatment group began training once reinnervation in the tibialis anterior muscle was detected, whereas those in the control group continued to use their ankle-foot orthosis full time. Differences in ankle dorsiflexion were measured using the Medical Research Council scale, and quantitative force measurement and functional disability was measured using the Stanmore Scale.

RESULTS

Patients in the gait training group attained significantly better functional recovery as measured by the Stanmore Scale (79.5 ± 14.3) (mean ± SD) versus (37.2 ± 3.5) in the control group (p = 0.02). Medical Research Council grades were 3.8 ± 0.6 in the training group versus 2.5 ± 1.2 in the surgery only group (p < 0.05). Average dorsiflexion force from patients with above antigravity strength (all from the training group) was 31 percent of the contralateral side.

CONCLUSION

In patients with successful reinnervation following tibial nerve transfers, rehabilitation training significantly improved dorsiflexion strength and function.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Prioritised challenges in the management of acute knee dislocations are stiffness, obesity, treatment delays and associated limb-threatening injuries: a global consensus study

OBJECTIVES

Heterogeneous patient factors and injury mechanisms result in a great variety of injury patterns encountered in knee dislocations (KD). Attempts to improve outcome can focus on a wide range of challenges. The aim of this study was to establish and prioritise a list of challenges encountered when treating patients with acute KD.

METHODS

A modified Delphi consensus study was conducted with international knee specialists who generated a prioritised list of challenges. Selected priorities were limited to half of the possible items. Agreement of more than 70% was defined as consensus on each of these items a priori.

RESULTS

Ninety-one international surgeons participated in the first round. The majority worked in public hospitals and treated patients from low-income and middle-income households. Their propositions were prioritised by 27 knee surgeons from Europe, Africa, Asia, as well as North and South America, with a mean of 15.3 years of experience in knee surgery (SD 17.8). Consensus was reached for postoperative stiffness, obesity, delay to presentation and associated common peroneal nerve injuries. Challenges such as vascular injuries, ipsilateral fractures, open injuries as well as residual laxity were also rated high. Most of these topics with high priority are key during the initial management of a patient with KD, at presentation. Topics with lower priority were postsurgical challenges, such as patient insight, expectations and compliance, rehabilitation programme, and pain management.

CONCLUSION

This consensus study has a wide geographical footprint of experts around the world practising in various settings. These participants prioritised stiffness, obesity, treatment delays and associated limb-threatening injuries as the most important challenges when managing a patient with acute KD. This list calls for applicable and feasible solutions for these challenges in a global setting. It should be used to prioritise research efforts and discuss treatment guidelines.

LEVEL OF EVIDENCE

V.

Routine knee MRI: how common are peripheral nerve abnormalities, and why does it matter?

OBJECTIVE

To evaluate the frequency, MRI appearance, and clinical significance of peripheral nerve abnormalities encountered on routine knee MRI.

MATERIALS AND METHODS

A retrospective review was performed to identify consecutive patients who underwent routine knee MRI from March 2015-2018 and had peripheral nerve abnormalities. MRIs were reviewed for the presence of tibial (TN) and common peroneal nerve (CPN) abnormalities (including hyperintensity, bulbous enlargement, discontinuity, architectural distortion, skeletal muscle denervation). The presence or absence of concomitant meniscal, cruciate, and collateral ligament tears was documented. Patient demographics and clinical outcomes were recorded. Descriptive statistics were reported.

RESULTS

The search yielded 8125 MRIs, of which 50 knee MRIs (patient age (years): 44 + 19) had peripheral nerve abnormalities (hyperintensity (TN: 30%(15/50), CPN: 80%(40/50)), bulbous enlargement (TN: 10%(5/50), CPN: 30%(15/50)), discontinuity (TN: 0, CPN: 4%(2/50)), architectural distortion (TN: 4%(2/50), CPN: 18%(9/50)), and skeletal muscle denervation (TN: 14%(7/50), CPN: 28%(14/50)). Medial meniscus (TN: 12% (6/50), CPN: 36%(18/50)), ACL (TN: 4%(2/50), CPN: 32%(16/50)), PCL (TN: 2%(1/50), CPN: 20%(10/50)), and lateral meniscus (TN: 12%(6/50), CPN: 24%(12/50)) tears were frequently present. Of these, 32% (16/50) were treated for peripheral nerve injury (PNI), characterized as high-grade (n = 7/16) or low-grade (n = 9/16). Nerve discontinuity, architectural distortion, and denervation were encountered more in high-grade PNI than low-grade PNI. Five patients were recalled for follow-up imaging and operative management was performed in 36% of cases (18/50).

CONCLUSION

Although uncommon (frequency = 0.6%), peripheral nerve abnormalities (CPN more common than TN) are encountered on routine knee MRI and affect patient management, with 36% requiring surgical treatment.

Common Peroneal Nerve Injury Related to Small Saphenous Vein Surgery: Report of 2 Cases and Review of the Literature

Although iatrogenic damage is less often involved, deep nerve injuries are reported especially as a result of small saphenous vein (SSV) dissection. Complete or partial division of the common peroneal nerve (CPN) during varicose vein operations causes substantial and serious disability. Most CPN injuries recover spontaneously; nonetheless, some require nerve surgery. Treatment depends on the nature of CPN injury. This report chronicles 2 instances of CPN injury after SSV surgery, addressing treatment strategies and therapeutic gains. The pertinent literature is also reviewed.

Distal biceps femoris avulsions: Associated injuries and neurological sequelae

BACKGROUND

The aim of this study was to describe associated injuries in cases of distal biceps femoris avulsions (DBFA) as well as the incidence of neurological injury and radiographic abnormalities of the common peroneal nerve (CPN).

METHODS

A retrospective chart review was conducted of patients presenting to our office or trauma center with DBFA injuries. Demographic data was obtained as well as mechanism of injury. Assessment of concomitant injuries and presence of neurologic injury was completed via chart review and magnetic resonance imaging (MRI) review. The CPN was evaluated for signs of displacement or neuritis.

RESULTS

Sixteen patients were identified (mean age-at-injury 28.6 years, 87.5% male) with DBFA. Three patients (18.8%) sustained their injuries secondary to high energy trauma while 13 (81.3%) had injuries secondary to lower energy trauma. Nine patients (56.3%) initially presented with CPN palsy. All patients presenting with CPN palsy of any kind were found to have a displaced CPN on MRI and no patient with a normal nerve course had a CPN palsy.

CONCLUSIONS

This case series demonstrates a strong association between DBFA and CPN palsy as well as multi-ligamentous knee injury (MLKI). These injuries have a higher rate of CPN palsy than that typically reported for MLKI. Furthermore, these findings suggest that CPN displacement on MRI may be a clinically significant indicator of nerve injury. LOE: IV.

Controversies in acute multiligamentary knee injuries (MLKI)

Multiligament injuries of the knee (MLKI), remain an infrequent pathology especially in developed countries compared to mono-ligament lesions. In Colombia, MLKI is frequent due to the high accident rate on motorcycles. In the city of Bogota alone, about 160 motorcycle accidents have been estimated daily, being one of the cities that proportionately use this means of transport less compared to small cities. The term MLKI, include all ruptures of two or more major ligaments and therefore it has a broad spectrum of clinical presentation which creates a great challenge for the orthopedists and the surgeons envolved in this topic. The literature is rich in studies level IV but very poor in level I and level II, which generates controversies and little consensus in the diagnosis and treatment of this pathology. However there has been a gradual and better understanding of all factors involved in the treatment of MLKI that has improved the functional results of these knees in our patients, in fact we currently are more precise to achieve accurate diagnosis, evolved from not surgical approach to operate most, applying new anatomical and biomechanical concepts, with specialized and skill surgical techniques with more stable and biocompatible fixation implants, which allow in most cases to initiate an early integral rehabilitation program. Nevertheless due to the complexity and severity of the lesions, in some patients the functional results are poor. The goal of this revision is to identify the most frequent controversies in the diagnosis and treatment of MLKI, defining which of them are agreed according to what is reported in the literature and share some concepts based from the experience of more than 25 years of the senior author (MM) in the management of these injuries. LEVEL OF EVIDENCE: V - Expert Opinion.

Management of multiligament knee injuries

Up to 18% of multiligament knee injuries (MLKI) have an associated vascular injury.All MLKI should be assessed using the ankle brachial pressure index (ABPI) with selective arteriography if ABPI is < 0.9.An ischaemic limb following knee dislocation must be taken to the operating theatre immediately for stabilization and re-vascularization.Partial common peroneal nerve (CPN) injury following MLKI has better recovery than complete palsy.Posterior tibial tendon transfer is offered to patients with complete CPN palsy if there is no recovery at six months.Operative treatment with acute or staged reconstructions provides the best outcome in MLKI.Effective repair can only be performed within three weeks of injury.There is no difference between repair and reconstruction of medial collateral ligament and posteromedial corner.Posterolateral corner reconstruction has a lower failure rate than repair.Early mobilization following MLKI surgery results in fewer range-of-motion deficits. Cite this article: EFORT Open Rev 2020;5:145-155. DOI: 10.1302/2058-5241.5.190012.

Knee dislocation and associated injuries: an analysis of the American College of Surgeons National Trauma Data Bank

PURPOSE

Knee dislocations (KDs) are potentially devastating injuries, leading to loss of function or limb in often young patients. This retrospective database review aims to determine the relative incidence and risk factors for KDs presenting to North American Level I and II trauma centers.

METHODS

The National Trauma Data Bank (NTDB) was retrospectively interrogated using ICD-9-CM codes to identify KDs between 2010 and 2014 to derive KD incidence. KDs were stratified by age, sex, Injury Severity Score (ISS), Glasgow Coma Scale (GCS), drug and alcohol use, injury mechanism, open vs. closed KD, vascular injury and fracture. Each co-variate was tested against different mechanisms of injury, using Chi-squared tests and risk adjusted analyses to derive risk factors for KD. The same calculations were done for secondary outcomes (vascular and neurological injuries, compartment syndrome, amputation, and mortality).

RESULTS

A total of 6454 KDs met the inclusion criteria (18/10,000 admissions). KDs occurred most commonly amongst men, aged 20-39, with an ISS score 1-14 and following motor vehicle collision (MVC). A vascular investigation was performed in 29%, with injury documented in 15% of KDs and 10.8% receiving a vascular procedure. Associated fractures were observed in 41.4% of KDs. Open injuries in 13.6%. Neurological injury documented in 6.2%, compartment syndrome in 2.7%, amputation in 3.8% (> 50% had vascular injury) and 2.8% died. MVC was the most common mechanism of injury (p < 0.001), significantly more common in young, male patients, associated with higher ISS and lower GCS, especially when drugs or alcohol were involved (p < 0.0001). Being male, having a vascular injury or open KD were all risk factors for compartment syndrome, amputation and neurological injuries.

CONCLUSIONS

KDs are rare injuries, but their relative incidence may be increasing. Young, male patients involved in MVCs are risk factors for KDs and their associated injuries, such as neurological injuries, amputations and compartment syndrome. Vascular injury occurs at a frequency of around 15%. The findings of the current study may guide future research and help to inform clinicians on the expected rates of associated injuries in patients identified to have KD in a trauma center population. It informs regarding risk factors for KD, which may improve diagnosis rates of spontaneously reduced knee dislocations by increasing index of suspicion in high-risk patients and identifies specific links with impaired driving.

LEVEL OF EVIDENCE

IV.

The multiple ligament-injured knee: When is primary repair an option?

BACKGROUND

Treatment of multiple ligament-injured knees (MLIKs) remains complex and most often requires ligament reconstruction surgery. Reconstruction effectively restores knee stability but the procedure is invasive and can be complicated by stiffness or arthrofibrosis. There has been recent resurgence of interest in primary repair of knee ligaments. The goal was therefore to assess incidence of repairable ligaments in MLIKs, and determine patient and injury characteristics associated with potential for primary repair.

METHODS

A retrospective review of all MLIK patients surgically treated between 2009 and 2018 was conducted. All patients were treated with the same algorithm: primary repair was performed if the ligament was proximally or distally avulsed, and otherwise, reconstruction was performed. Patient characteristics, injury patterns, treatment specifics, and short-term outcomes were compared using independent t-tests and chi-square tests.

RESULTS

Forty-eight patients were included (mean age 32 years ± 14; 54% were male). Ultimately, 55% of ACL, 73% of PCL, 88% of MCL/PMC, and 87% of LCL/PLC injuries were repaired. Patients above 35 years (OR 6.9, P = 0.010) and higher BMI (OR 3.5, P = 0.046) were more likely to undergo ACL repair. No significant correlation was found in other ligaments. At a minimum of six-month follow-up (range 0.5-7.2 years), ACL repair failed in nine percent, PCL repair in 17%, MCL/PMC repair in 0%, and LCL/PLC repair in 18% of patients.

CONCLUSIONS

This study noted high incidences of repairable ligaments when MLIKs are treated within six weeks following injury. Although preliminary outcomes following primary repair in MLIK are good, further long-term follow-up studies are needed.

Knee and Leg Injuries

Knee and leg injuries are extremely common presentations to the emergency department. Understanding the anatomy of the knee, particularly the vasculature and ligamentous structures, can help emergency physicians (EPs) diagnose and manage these injuries. Use of musculoskeletal ultrasonography can further aid EPs through the diagnostic process. Proper use of knee immobilizers can also improve long-term patient outcomes.

Critical Evaluation of the Methodologic Quality of the Top 50 Cited Articles Relating to Knee Dislocation and Multiligamentous Knee Injury

Background:

Many studies have evaluated the management of knee dislocations (KDs) and multiligamentous knee injuries (MLKIs). However, no study to date has analyzed the quality of the most cited articles in this literature.

Hypothesis:

There is a positive correlation between the number of article citations in the KD and MLKI literature and their methodologic quality.

Study Design:

Systematic review.

Methods:

The Web of Science online database was searched to identify the top 50 cited articles in KD and MLKI care. Demographic data were recorded for each study. The Modified Coleman Methodology Score (MCMS) and the Methodological Index for Non-randomized Studies (MINORS) were used to analyze the methodological quality of each article. Spearman correlation coefficients (r_s) were then calculated.

Results:

The articles identified were published between 1958 and 2015 in a wide variety of peer-reviewed journals (n = 16). The majority of study level of evidence (LOE) was of low quality (level 5, 16%; level 4, 54%; level 3, 16%; level 2, 14%). There were no studies of level 1 evidence. The mean MCMS and MINORS scores were 29.0 (SD, 19.1; range, 3-72) and 6.1 (SD, 3.7; range, 0-14), respectively. No significant correlation was identified between the number of citations and the publication year, LOE, MCMS, or MINORS (r_s = 0.123 [P = .396]; r_s = 0.125 [P = .389]; r_s = 0.182 [P = .204]; and r_s = 0.175 [P = .224], respectively). Positive correlations were observed between improved MCMS and MINORS scores and more recent year of publication (r_s = 0.43 [P = .002]; r_s = 0.32 [P = .022]) as well as improved study LOE (r_s = 0.65 [P < .001]; r_s = 0.67 [P < .001]).

Conclusion:

The top 50 cited articles on KD and MLKI care consisted of low LOE and methodological quality, with no existing level 1 articles. There was no significant correlation between the number of citations and publication year, LOE, or study methodological quality. Positive correlations were observed between later publication date and improved methodological quality.

Functional evaluation of early tendon transfer for foot drop

AIM

Early tendon transfer has shown good outcomes in peripheral nerve injuries of upper limb. However, there is lack of knowledge on early tendon transfer for peripheral nerve palsy in lower limb. This study has been designed to study the functional outcomes of early tendon transfer in the lower limb, particularly for foot drop.

PATIENTS AND METHODS

We enrolled 30 cases of foot drop due to traumatic sciatic/common peroneal nerve (CPN) palsy between September 2012 and March 2016. We performed nerve exploration with repair and early tendon transfer in all patients. All patients were followed up for a minimum period of 24 months. Functional evaluation was carried out using Stanmore assessment questionnaire.

RESULTS

At the end of 24 months postoperatively, the Stanmore assessment questionnaire score showed a significant improvement from a mean preoperative score of 17.5 to mean postoperative score of 86.2. All patients were free of ankle-foot orthosis (AFO). All patients were subjectively satisfied. Time to return to original job was 5.2 months on an average. Ankle dorsiflexion of the operated limb was comparable to the normal limb in cases where there was nerve recovery. Planovalgus foot, a known complication of this procedure, was noted in 24 patients. However, it was not disabling to any patient.

CONCLUSION

Early tendon transfer in CPN palsy/sciatic nerve palsy has a definite place in the management of the injured patient. The transfer, if appropriately carried out, acts as a helper, an internal splint, a substitute, or perhaps all of the three at varying times in the rehabilitative phase of the patient. Dorsiflexor clearance in swing phase of locomotion was quickly restored in all patients, obviating the need for AFO.

Ultrasound Evaluation and Surgical Excision of a Fabella Causing Peroneal Neuropathy in a Track Athlete

Background

There are multiple causes of posterior knee pain and radicular symptoms. A symptomatic fabella is a rare cause but should be considered in the differential diagnosis.

Purpose

Physicians should consider a symptomatic fabella as a diagnosis when common treatments for posterior knee pain have not alleviated the symptoms.

Study Design

Case report.

Methods

Review of clinical documentations of an orthopedist, physiatrist, physical therapist, 2 primary care sports medicine physicians, and the surgical report of an orthopedist.

Results

It took time and resources including several referrals and imaging modalities to make a final diagnosis.

Conclusion

Symptomatic fabellae are an uncommon finding but should be considered in the differential diagnosis with an athlete with posterior knee pain.

Clinical Relevance

Considerable time and resources were used to ultimately diagnose and treat a NCAA Division 1 athlete. Surgical excision was required of a sesamoid bone that is present in 30% of individuals.

Repair and Augmentation with Internal Brace in the Multiligament Injured Knee

The internal brace is a ligament repair bridging concept using braided ultra-high-molecular-weight polyethylene suture tape and knotless bone anchors to reinforce ligament strength to allow early mobilization during early-phase healing. This concept can be used in the management of anterior cruciate ligament, posterior cruciate ligament, anterolateral ligament, medial collateral ligament, posteromedial corner, and posterolateral corner injuries. Ligament reinforcement is a concept in which a graft is reinforced and can be used in all aspects of knee ligament reconstruction. There has been a recent resurgence in ligament repair and recent evidence suggests equivalent outcome results.

The Biomechanics of Multiligament Knee Injuries: From Trauma to Treatment

The multiple ligament injured knee is a complex biomechanical environment. When primary stabilizers fail, secondary stabilizers have an increased role. In addition, loss of primary restraints puts undue stress on the remaining intact structures of the knee. Treatment of these injuries requires accurate diagnosis of all injured structures, and careful consideration of repairs and reconstructions that restore the synergistic stability of all ligaments in the knee.

National Athletic Trainers' Association Position Statement: Immediate Management of Appendicular Joint Dislocations

OBJECTIVE

To provide certified athletic trainers (ATs) with recommendations and guidelines for the immediate management of patients with joint dislocations.

BACKGROUND

One of the primary responsibilities of ATs is to provide immediate injury care for active individuals. Although ATs are confronted with managing patients who have many kinds of injuries, the onsite management of a joint dislocation presents challenges in evaluation and immediate treatment. The critical concern in managing a dislocation is deciding when a joint can be reduced onsite and when the patient should be splinted and transported for reduction to be performed in the hospital or medical setting. Factors that influence the decision-making process include the following: whether the AT possesses a documented protocol that is supported by his or her supervising physician(s), employer documents, and respective state regulations; the AT's qualifications and experience; the dislocated joint; whether the dislocation is first time or recurrent; the patient's age and general health; and whether associated injuries are present.

RECOMMENDATIONS

These guidelines are intended to provide considerations for the initial care of specific joint dislocations. They are not intended to represent the standard of care and should not be interpreted as a standard of care for therapeutic or legal discussion.

Allograft for the treatment of traumatic severe bone loss in the lateral femoral condyle: A case report

BACKGROUND

Open articular fractures are an important issue due to their increasing incidence, along with the rise in motorcycle accidents. Oncology experience with allograft in orthopedics may be extended to cases of traumatic bone loss.

CLINICAL CASE

A 37-year-old man with an open fracture of the distal femur and proximal tibia presented a massive bone loss of the lateral femoral condyle after a motorcycle accident. Following Damage Control Surgery, a considerable lateral femoral condyle allograft was used to restore the joint anatomy.

RESULTS

After an intensive rehabilitation program and two subsequent arthroscopic arthrolyses, the patient resumed walking without aids and recovered from stiffness (R.O.M. 0-130°). An MRI performed at median follow-up, revealed a favorable integration of the allograft.

DISCUSSION

Allografts are a reasonable reconstructive option for young individuals with massive bone loss. An appropriately sized allograft is essential to restore an acceptable function as seen in the herein case.

Association of Injury Energy Level and Neurovascular Injury Following Knee Dislocation

OBJECTIVE

To describe the associations between mechanism of injury energy level and neurovascular injury (NVI) following knee dislocation (KD) using a large representative sample of trauma patients and to examine risk factors within these groups.

DESIGN

Retrospective cohort study.

SETTING

Trauma centers participating in the American College of Surgeons National Trauma Data Bank.

PARTICIPANTS

Adult patients with KD without lower extremity fracture.

INTERVENTION

Patients were grouped as ultra-low, low, or high-energy based on injury mechanism. Univariate/multivariate analyses assessed associations of energy level with NVI and of patient characteristics with NVI within energy-level groups.

MAIN OUTCOME MEASUREMENTS

Rate of nerve and blood vessel injury.

RESULTS

One hundred twenty-four patients with KD were identified; 181 sustained ultra-low-energy mechanisms, 275 low-energy, and 868 high-energy. Nerve injury occurred in 6% of ultra-low-energy injuries, 7% in low-energy, and 3% in high-energy (P = 0.03). Vessel injury occurred in 21% of ultra-low-energy injuries, 17% in low-energy, and 13% in high-energy (P = 0.01). On multivariate analyses, obesity was associated with nerve injury in the ultra-low-energy group (OR 4.9; 95% CI 1.0-24.0) but not with other energy levels. Obesity was also associated with vessel injury in the ultra-low-energy group (OR 4.0; 95% CI 1.6-9.7). Smoking, hypertension, and diabetes were not associated with NVI.

CONCLUSIONS

NVI following KD is more common after lower energy-level mechanisms. Obesity is associated with NVI in lower energy-level mechanisms. Physicians should be vigilant in screening for NVI in the setting of KD even with seemingly benign mechanisms of injury, especially in patients with obesity.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.