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.

Arthrofibrosis after ACL reconstruction is best treated in a step-wise approach with early recognition and intervention: a systematic review.

PURPOSE: Arthrofibrosis is the most common post-operative complication of anterior cruciate ligament (ACL) reconstruction. Risk factors and management strategies for arthrofibrosis remain unclear. The purpose of this review was to: (a) describe existing definitions of arthrofibrosis, and (b) characterize the management strategies and outcomes of arthrofibrosis treatment. METHODS: MEDLINE, EMBASE, and PubMed were searched from database inception to search date (March 21, 2016) and screened in duplicate for relevant studies. Data regarding patient demographics, indications, index surgery, management strategy, and outcomes were collected. RESULTS: Twenty-five studies of primarily level IV evidence (88%) were included. A total of 647 patients (648 knees) with a mean age of 28.2 ± 1.8 years (range 14-62 years) were treated for arthrofibrosis following ACL reconstruction and followed for a mean 30.1 ± 16.9 months (range 2 months-9.6 years). Definitions of arthrofibrosis varied widely and included subjective definitions and the Shelbourne classification system. Patients were treated by one or more of: arthroscopic arthrolysis (570 patients), manipulation under anaesthesia (MUA) (153 patients), oral corticosteroids (31 patients), physiotherapy (81 patients), drop-casting (17 patients), epidural therapy combined with inpatient physiotherapy (six patients), and intra-articular interleukin-1 antagonist injection (four patients). All studies reported improvement in range of motion post-operatively, with statistically significant improvement reported for 306 patients (six studies, p range <0.001 to =0.05), and one study (18 patients) reporting significantly better results if arthrofibrosis was treated within 8 months of reconstruction (p < 0.03). The greatest improvements for extension loss were seen with drop-casting (mean 6.2° ± 0.6° improvement), whereas MUA produced the greatest improvement for flexion deficit (mean 47.8° ± 3.3° improvement). CONCLUSIONS: Arthrofibrosis is poorly defined and outcome measures range varies widely. Amongst the studies included in this review, arthrofibrosis was most commonly managed surgically by arthroscopic arthrolysis, and most patients showed at least some improvement, including six studies that reported statistically significant change in ROM. In studies that used a step-wise approach to treating arthrofibrosis, more than half of patients were successfully treated without an operation. A more well-defined concept of arthrofibrosis, along with large, prospective studies will provide a clearer understanding of how to describe and manage this complication. The issue of arthrofibrosis following ACL reconstruction is clinically relevant as it represents a common complication of a commonly performed operation that nonetheless remains poorly defined and without clear treatment guidelines. LEVEL OF EVIDENCE: Systematic Review of Level III and IV Studies, Level IV.

Maximum load to failure and tensile displacement of an all-suture glenoid anchor compared with a screw-in glenoid anchor.

PURPOSE: The purpose of this study was to evaluate the biomechanical behavior of an all-suture glenoid anchor in comparison with a more conventional screw-in glenoid anchor, with regard to maximum load to failure and tensile displacement. METHODS: All mechanical testing was performed using an Instron ElectroPuls E1000 mechanical machine, with a 10 N pre-load and displacement rate of 10 mm/min. Force-displacement curves were generated, with calculation of maximum load, maximum displacement, displacement at 50 N and stiffness. Pretesting of handset Y-Knots in bone analog models revealed low force displacement below 60 N of force. Subsequently, three groups of anchors were tested for pull out strength in bovine bone and cadaver glenoid bone: a bioabsorbable screw-in anchor (Bio Mini-Revo, ConMed Linvatec), a handset all-suture anchor (Y-Knot, ConMed Linvatec) and a 60 N pre-tensioned all-suture anchor (Y-Knot). A total of 8 anchors from each group was tested in proximal tibia of bovine bone and human glenoids (age range 50-90). RESULTS: In bovine bone, the Bio Mini-Revo displayed greater maximum load to failure (206 ± 77 N) than both the handset (140 ± 51 N; P = 0.01) and the pre-tensioned Y-Knot (135 ± 46 N; P = 0.001); no significant difference was seen between the three anchor groups in glenoid bone. Compared to the screw-in anchors, the handset all-suture anchor displayed inferior fixation, early displacement and greater laxity in the bovine bone and cadaveric bone (P < 0.05). Pre-tensioning the all-suture anchor to 60 N eliminated this behavior in all bone models. CONCLUSIONS: Handset Y-Knots display low force anchor displacement, which is likely due to slippage in the pilot hole. Pre-tensioning the Y-Knot to 60 N eliminates this behavior. LEVEL OF EVIDENCE: I.

Anatomical considerations in multiligament knee injury and surgery.

The management of multiligament knee injury mandates a comprehensive understanding of the anatomy on all sides of the joint. Imperative to repair or reconstructive procedures is an intimate knowledge of the structure of the cruciate and collateral ligaments, as well as the complex confluence of structures that comprise the posteromedial and posterolateral corners. Beyond the ligamentous anatomy, the surgeon must also be aware of the potential for neurologic and vascular compromise-both from injury and from treatment-that can often complicate multiligament knee injuries. In this article, we outline the basic anatomy and biomechanical function of the ligamentous structures of the knee, structures at risk, and the patterns of injury seen with knee dislocations and multiple ligament knee injuries in general.

Outcomes of treatment of multiple ligament knee injuries.

Knee dislocations are rare and potentially devastating injuries. Significant displacement of the tibia and femur commonly disrupts multiple knee ligaments and also often results in profound disruption to the surrounding soft tissue envelope. Open wounds and neurologic and vascular insult can put the involved limb in jeopardy. Following reduction, the optimal management of the dislocated knee is unknown. Surgery to repair and/or reconstruct torn structures likely affords superior long-term function over nonoperative immobilization strategies. The role of early versus delayed surgery, repair versus reconstruction, and autograft versus allograft tissue for reconstruction remain topics of debate. High-quality research efforts to investigate these controversies are hampered by the heterogeneous nature of the injuries themselves and the many treatment strategies available.

The development and validation of a quality of life-measurement tool for patients with meniscal pathology: the Western Ontario Meniscal Evaluation Tool (WOMET).

OBJECTIVE: To develop and validate a disease-specific, health-related quality of life (HRQOL) index for patients with meniscal pathology. Our hypothesis was that the Western Ontario Meniscal Evaluation Tool (WOMET) would provide adequate reliability, validity, and responsiveness in measuring HRQOL in patients with meniscal tears or who have undergone meniscal repair or resection. STUDY DESIGN: Validation of a measurement tool. SETTING: A tertiary, university-affiliated, sport medicine clinic. PARTICIPANTS: A methodological protocol based on that of Guyatt et al was used to develop the Western Ontario Meniscal Evaluation Tool (WOMET). Patients with meniscal symptomology and in whom magnetic resonance imaging had suggested meniscal pathology were selected from referrals to a sport medicine clinic. Using this cohort, the development of the WOMET proceeded through item generation, reduction, and instrument pretesting. A second cohort of postarthroscopy patients with confirmed meniscal pathology was used to assess the reliability of the WOMET and validate the instrument. RESULTS: The final instrument has 16 items representing the domains of physical symptoms (nine items), sports/recreation/work/lifestyle (four items), and emotions (three items). It demonstrated adequate content and construct validity when compared with other measures. Test-retest reliability was assessed and was found to be high, with an intraclass correlation coefficient of 0.833. The new instrument was also found to be more responsive than other knee measurement tools when assessed in the same cohort. CONCLUSIONS AND CLINICAL RELEVANCE: The WOMET is a disease-specific tool designed to evaluate HRQOL in patients with meniscal pathology. It is therefore put forth as a validated measurement tool to be used in clinical trials evaluating treatments for meniscal pathology. It could also be used as a prospective outcome measure in research or in clinical practice.