A multiligament, internal brace, coaptationless stifle reconstruction technique for feline stifle luxation.

To evaluate the surgical procedure and short-term effectiveness of one-stage repair and reconstruction of knee dislocation with multiple ligament injuries (KDMLI). Between September 2010 and April 2014, 9 cases (9 knees) of KDMLI were treated. There were 7 males and 2 females with an average age of 42 years (range, 27-57 years). Injury was caused by traffic accident in 3 cases, heavy-weight crushing in 3 cases, sports sprain in 2 cases, and falling from height in 1 case. The average time from injury to operation was 11 days (range, 3-19 days). The results of posterior drawer test and Lachman test were positive in all patients. The results of varus stress testing were three-degree positive in 4 cases, and the results of valgus stress testing were three-degree positive in 6 cases. The Lysholm score of knee was 27.2±6.3; the International Knee Documentation Committee (IKDC) score was 29.7±6.5; and the range of motion (ROM) was (52.6±12.8)°. All patients suffered from posterior cruciate ligament (PCL) injury and femoral avulsion injury of anterior cruciate ligament (ACL). Combined injuries included medial collateral ligament (MCL) injury in 4 cases (medial meniscus injury in 1 case), lateral collateral ligament (LCL) injury in 2 cases, and MCL and LCL injuries in 2 cases (medial meniscus and lateral meniscus injuries in 1 case). Autologous harmstring tendon was used to reconstruct PCL under arthroscopy combined with limited open in situ suture for repair of femoral avulsion injury of ACL, and repair of MCL, LCL, and other injury in one-stage operation. All incisions healed by first intention. Joint effusion of knee occurred in 1 case and was cured after removal of fluid combined with pressure bandage. All patients were followed up 12-36 months with an average of 22 months. At last follow-up, the result of posterior drawer test was negative in all patients. The results of Lachman test were one-degree positive in 2 cases; the result of varus stress testing was one-degree positive in 1 case; the results of valgus stress testing were one-degree positive in 2?cases; and flexion dysfunction of the knee was observed in 1 case. The Lysholm score of knee was 87.3±6.6; the IKDC score was 88.9±6.8; and the ROM was (121.7±12.3)°, all showing significant differences when compared with preoperative ones (t=44.246, P=0.000; t=37.903, P=0.000; t=19.894, P=0.000). For KDMLI, one-stage repair and reconstruction using autologous harmstring tendon to reconst ruct PCL under arthroscopy combined with limited open in situ suture repair of femoral avulsion injury of ACL, and repair MCL, LCL, and other injury has such advantages as minimal invasiveness, reliable fixation, less complications, and fast recovery, which can significantly improve the stability, ROM, and function of knee and obtain good short-term effectiveness.

Sonographic Examination of Knee Ligaments.

Background: Objective data on chronic injuries of the medial collateral ligament (MCL) of the ankle are scarce. Chronic MCL injuries are frequently associated with lateral collateral ligament (LCL) injuries. For patients with chronic combined MCL and LCL injuries, the authors have performed simultaneous surgery of the 2 ligaments. Hypothesis: Simultaneous surgery of the 2 ligaments may be effectively used to treat chronic combined MCL and LCL injuries. Study Design: Case series; Level of evidence, 4. Methods: Surgical outcomes were evaluated in 29 consecutive patients presenting with chronic MCL and LCL injuries (30 ankles; 15 men and 14 women; mean age, 31 years; 13 competitive and 10 recreational athletes). Preoperative and postoperative clinical outcomes were measured with the Karlsson score and the Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale score. The patients underwent preoperative and postoperative functional measurements and a radiological examination. In addition, preoperative magnetic resonance imaging (MRI) results, arthroscopic findings, and histology of the MCL were evaluated. Results: Preoperatively, the deep fibers of the MCL did not appear striated in 29 ankles, and high-intensity signal changes were observed in 23 ankles on T2-weighted or gradient echo MRI. MCL ruptures were confirmed with arthroscopic surgery. Medial impingement lesions and focal chondral lesions were confirmed in 10 and 21 ankles, respectively. Histology of the reconstructed MCL showed dense collagen fibers with vessels. The mean postoperative follow-up period was 30 months (range, 24-52 months). There was a significant change between preoperative and postoperative Karlsson scores (69.0 vs 96.1 points, respectively; P < .0001) and JSSF scores (69.8 vs 94.5 points, respectively; P < .0001). On varus and valgus stress radiography, the postoperative talar tilt angle was significantly lower than the preoperative angle. Postoperative anterior displacement on stress radiography was significantly lower than preoperative anterior displacement. Postoperatively, all 23 athletes returned to their preinjury level of sports participation. Conclusion: MCL insufficiency resulted from medial ankle instability and medial impingement lesions. Outcomes in the patients indicated that MCL reconstruction or resection of medial impingement lesions, performed in addition to LCL reconstruction, is effective for treating chronic combined MCL and LCL injuries of the ankle.

BackgroundThere is limited epidemiological information on injury rates and injury mechanisms for lateral collateral ligament (LCL) and posterior cruciate ligament (PCL) injuries in male professional soccer. In addition, time trends and lay-off times for these injuries have not yet been determined.AimTo determine injury rates and circumstances of LCL and PCL injuries over 17 seasons in men’s professional soccer.MethodsA prospective cohort study, in which 68 professional European soccer teams were followed over 17 consecutive seasons (2001/2002 to 2017/2018). The teams’ medical staff recorded player exposure and time-loss injuries. Lay-off time was reported as the median and the first and third quartile. Injury rate was defined as the number of injuries per 1000 player-hours.ResultsOne hundred and twenty-eight LCL and 28 PCL injuries occurred during 2,554,686 h of exposure (rate 0.05 and 0.01/1000 h, respectively). The median lay-off time for LCL injuries was 15 (Q1=7, Q3=32) days, while it was 31 days for PCL injuries (Q1=15, Q3=74). The match injury rate for LCL injuries was 11 times higher than the training injury rate (0.21 vs 0.02/1000 h, rate ratio [RR] 10.5, 95% CI 7.3 to 15.1 p<0.001) and the match injury rate for PCL injuries was 20 times higher than the training injury rate (0.056 vs 0.003/1000 h, RR 20.1, 95% CI 8.2 to 49.6, p<0.001). LCL injuries saw a significant annual decrease of approximately 3.5% (p=0.006). In total, 58% (63/108) of all LCL injuries and 54% (14/26) of all PCL injuries were related to contact mechanism.ConclusionThis study with prospectively registered data on LCL and PCL injuries in men’s professional soccer shows that the median lay-off from soccer for LCL and PCL injuries is approximately 2 and 4 weeks respectively. These rare knee ligament injuries typically occur during matches and are associated with a contact injury mechanism.

Background The coronoid process is an important stable structure of the elbow joint. The coronoid process is formed by the forward and medial extension of the proximal metaphysis of the ulna, which increases the area of the joint matching the humerus block and maintains the stability of the elbow varus. However, nearly 60% of the anteromedial articular surface lacks the bony support of the metaphysis. Under the varus stress, it is easy to cause fracture, which leads to varus posterior medial rotational instability of the elbow. According to the characteristics of the coronoid fracture, O’Driscoll divided the fracture into three parts, the tip, the anteromedial side and the base according to the fracture location and injury mechanism. Among them, type 2 fracture, anteromedial articular surface fracture, was divided into three subtypes, type 2-1, anteromedial side fracture; type 2-2, anteromedial side + tip fracture; type 2-3, anteromedial Articular surface + sublime fractures ± tip fractures. O'Driscoll believes that the mechanism of injury to type 2 fractures is varus-posterior medial rotational instability, which is often accompanied by complete or partial rupture of the lateral collateral ligament. Methods 1. General information: In this retrospective analysis, from July 2012 to July 2016, Tianjin Hospital received 19 patients with anteromedial fractures of the ulnar coronoid process, including 17 males and 2 females, aged 22-58 years, with an average of 37.1 years. All 19 patients were freshly injured and had no open wounds. Causes of injury: 14 cases were falls and 5 cases were car accidents, which showed swelling of the elbow joint, pain, limited mobility, and no obvious neurological and vascular symptoms. Among them, 6 patients with elbow dislocation, closed reduction in emergency department, were all achieved; 1 patient had comminuted fracture of the distal radius; 1 patient had arthritis in the elbow joint. 2. Preoperative evaluation: Preoperative examination includes the patient's skin, soft tissue swelling, presence or absence of dislocation, with or without blood vessels, nerve damage. The anterior-posterior and lateral X-ray films of the elbow joint and the three-dimensional CT of the elbow joint were routinely examined before operation. MRI examination was used to determine the integrity of the medial and lateral collateral ligament. The preoperative dislocation was restored and the elbow was immobilized at 90 degrees. 3. Surgical method: Brachial plexus block anesthesia was used. First fix the coronoid process, the incision uses the ulnar carpi flexor approach: 2-3 cm up the medial epicondylar center, extending down 5-6 cm to the forearm longitudinal axis. Cut the skin and subcutaneous tissue in turn, and pull open to both sides of the incision, reveal the ulnar nerve, first reveal the release to the medial muscle interval, and then reveal between the two ends of the ulnar carpi flexor, free the first muscle branch. Support, give protection, lead to the posterior side, turn the ulnar carpi flexor tendon and the entire flexor tendon forward, the broken joint capsule and displaced fracture block could be seen. Clear the fracture end. According to the size and position of the fracture block, the steel plate, the screw and the auxiliary lasso are selected to fix the anterior joint capsule. Through the incision, the integrity of the medial collateral ligament is checked under direct vision. Once there is tearing, anchor reconstruction and the suture of the collateral ligament would be done. After fixation of the coronoid process and the medial structure was repaired, the forearm pronation position and neutral position were given. Under the C-arm fluoroscopy, the varus stress was applied respectively to see if the medial space of the ulnar joint was narrowed, and whether the lateral joint space was widened. If there was significant widening, suggesting that the lateral collateral ligament complex was damaged. The Kocher approach was used. The lateral collateral ligament was checked from humeral insertion to ulna insertion, repair using suture anchor was indicated if tear was confirmed. After repairing, look at the medial and lateral gaps again under C-arm fluoroscopy to determine the stability of the elbow joint. 4. Postoperative treatment: All patients were treated with hinged splint at 90-degree of flexion for 3 days. Under the protection of the hinge brace, the autonomous passive flexion and extension activities were performed, the extetion was not more than 30 degrees, and the forearm was in the neutral position after 3 days. After 6 weeks, the active flexion and extension exercises were carried out, and the flexion and extension angle were not restricted. After 12 weeks, the brace was used intermittently, and after 4 months, the normal life was gradually restored. 5. Eficacy evaluation: Postoperative evaluations use the Mayo elbow performance score (MEPS) , disability of arm shoulder and hand (DASH) and visual analogue scale (VAS) Evaluation of elbow joint function and symptoms. X-ray films were reviewed periodically after surgery, and osteoarthritis was graded using the Broberg-Morrey imaging score. Results All patients underwent anatomical reduction of ulnar coronoid process fractures, no fracture fixation failure, no ulnar coronectomy or bone grafting. One patient with a distal radius fracture and one patient had a history of arthritis were excluded. All other patients were followed up for a period of 12-30 months with an average of 19.7 months. The coronoid process was healed after operation, and no fracture malunion and internal fixation failure were found. Type of fracture: O'Driscoll 2-1 type 4 cases, 2-2 type 9 cases, 2-3 type 4 cases. Cases of elbow dislocation: 6 cases; varus stress test (-) , 4 cases of unrepaired lateral ligament, varus stress test (+) , repair of lateral collateral ligament: 13 cases; intraoperative medial collateral ligament found rupture and repair: 3 cases; at the last follow-up, the patient's elbow function score was recorded: MEPS: 85-100 points, mean: 97.6 points, excellent 16 cases, good 1 case; DASH: 0-10.8 points, average : 4.13 points; VAS: 0-2 points, average: 0.4 points; arthritis 5 cases of I degree. According to the fracture type grouping, non-parametric test was used to analyze whether the functional scores of type 1, 2, and 3 fractures were significantly different. On the basis of effective fixation of coronoid fractures, the multilateral analysis of the lateral collateral ligament repair, whether to repair the medial collateral ligament, arthritis grade and the presence of joint dislocation, the impact on joint function score. The arthritis and functional scores were assessed by Spearman test. all are not-significant different. Conclusions The injury mechanism of the anteromedial coronoid process is the fracture and instability of the elbow joint caused by the varus-posterior medial rotation, often with partial or complete rupture of the lateral ligament complex. After the medial bone mass is effectively fixed in the anterior coronoid process, the varus test can truly reflect the injury of the lateral ligament and the stability of the elbow joint. Under the premise of stable elbow joint, the lateral collateral ligament can be under the protection of the brace, functional exercise can achieve good treatment results. Key words: Elbow joint; Anteromedial coronoid fracture; Fracture fixation; Lateral collateral ligament injury; Ligament repair

To describe the incidence of soft-tissue injuries in patients with surgically treated Schatzker type IV tibial plateau fractures. All tibial plateau fractures in skeletally mature patients treated operatively between January 2013 and August 2018 were retrospectively reviewed using a clinical medical record system. All fractures were categorized according to the AO/OTA classifications. Twenty-seven patients with Schatzker type IV tibial plateau fractures were further classified based on the Wahlquist classification. Associated soft-tissue injuries, which consisted of cruciate ligament injuries, and meniscal and collateral ligament injuries, were diagnosed through operation notes and magnetic resonance imaging (MRI) data. The categorical variables were tested by the chi-square test or Fisher's exact test. The incidence of lateral meniscus tears and medial meniscus tears was 63% and 44.4% in Schatzker type IV tibial plateau fractures, respectively. Twenty-five (92.6%) patients had sustained anterior cruciate ligament (ACL) injuries, and 19 (70.4%) patients had an incomplete injury of the posterior cruciate ligament (PCL). There were 17 (63%) lateral collateral ligament (LCL) injuries, and 8 (29.6%) medial collateral ligament (MCL) injuries. Using the Wahlquist classification, these fractures were categorized as follows: type A, one patient; type B, six patients; type C, twenty patients. There was no significant difference between the type of fracture and the location of soft tissue injuries. This study found that operative Schatzker type IV tibial plateau fractures represented a high incidence of soft-tissue injuries, especially LCL injuries, ACL injuries, and meniscus tears. Based on our data, we believe that soft-tissue injuries in operative Schatzker type IV tibial plateau fractures deserve more attention.

Multiligament knee injuries (MLKIs) due to high-energy (HE) or polytraumatic (PT) mechanisms result in worse patient outcomes after surgery versus low-energy (LE) or nonpolytraumatic (NPT) mechanisms. There remains a paucity of research in the literature investigating MLKIs resulting from these mechanisms of injury. To characterize differences in ligamentous injury/surgery patterns between different mechanism groups: HE versus LE and PT versus NPT. Cross-sectional study; Level of evidence, 3. This is a retrospective chart review of consecutive surgical MLKIs from a single institution. Demographics, clinical/radiographic findings, and intraoperative variables were obtained. HE versus LE mechanisms were stratified. Patients with inadequate data were excluded. PT versus NPT classifications were based on presence of concurrent nonknee injuries. Subgroup comparisons were made based on body mass index, age, sex, number/type of ligaments injured, and surgeries performed. From a total of 226, 176 (78%) patients were included (41 PT [23%] and 135 NPT [77%]; 62 HE [35%] and 114 LE [65%]). PT mean age was 30.7 ± 13.7 years (male, 32 [78%)], while NPT mean age was 27.1 ± 12.3 years [male, 91/135 [67%]). HE mean age was 31.4 ± 13.1 years (male, 49/62 [79%]), and LE mean age was 25.6 ± 11.8 years (male, 73/114 [64%]). Posterior cruciate ligament (PCL) injuries were higher in PT (27/41 [66%]) and HE (42/62 [68%]) versus NPT (58/135 [43%]) and LE (44/114 [39%]), respectively. Lateral collateral ligament (LCL) injuries were higher in PT (29/41 [71%]) and HE (41/62 [66%]) versus NPT (66/135 [49%]) and LE (55/114 [48%]), respectively. The mean number of ligaments injured was higher in PT versus NPT (2.9 vs 2.4) and in HE versus LE (2.8 vs 2.4). LCL surgical interventions were more common in PT (23/41 [55%]) versus NPT (49/135 [36%]) and in HE (33/62 [53%]) versus LE (39/114 [34%]). No other differences in injuries/surgeries existed between PT and NPT or HE and LE, in anterior cruciate, medial collateral, or medial patellofemoral ligaments. PT and HE MLKIs are characterized by increased rates of PCL and LCL injuries compared with LE and NPT. HE and PT patients experience more injured ligaments than LE and NPT and are more likely to require reconstruction/repair of the LCL. These findings suggest injury severity and mechanism may facilitate clinical decision making in MLKIs.

Rehabilitation of the Medial- and Lateral Collateral Ligament-deficient Elbow: An In Vitro Biomechanical Study

To seek the factors associated with timing, staging, and type of surgery in the management of multiligament knee injuries. Cross-sectional scenario-based experiment. Fifteen fictional patient scenarios with randomized elements. Fracture surgeons of the Science of Variation Group, an international collaborative of musculoskeletal surgeons who studies variation in care, were invited to participate. Surgeons with limited experience treating multiligament knee injuries were asked to self-exclude. Surgeon recommendations for operative treatment, timing of surgery, and use of open surgery in addition to arthroscopy were measured. Patient factors (age, time from injury, contralateral fracture, knee dislocation, combinations of ruptured ligaments, and preexisting osteoarthritis) and surgeon factors (gender, practice location, years of experience, and supervision of trainees) associated with surgeon recommendations were assessed. Eighty-five surgeons participated, of which most were men (89%) and practiced in the United States (44%) or Europe (38%). Operative treatment was less likely among older patients (odds ratio [OR] = 0.051) and preexisting osteoarthritis (OR = 0.32) and more likely in knee dislocation (OR = 1.9) and disruption of anterior cruciate ligament, posterior cruciate ligament, and lateral collateral ligament with or without medial collateral ligament (MCL; OR = 5.1 and OR = 3.1, respectively). Disruption of anterior cruciate ligament, posterior cruciate ligament, and medial collateral ligament was associated with shorter time to surgery (β = -11). Longer time to surgery was associated with contralateral fracture (β = 9.2) and surgeons supervising trainees (β = 23) and practicing in Europe (β = 13). Surgeon factors accounted for more variation in timing than patient and injury factors (5.1% vs. 1.4%, respectively). Open surgery was more likely in patients with lateral collateral ligament injury (OR = 2.9 to 3.3). The observation that surgeons were more likely to operate in younger patients with more severe injury has face validity, while the finding that surgeon factors accounted for more variation in timing of surgery than patient or injury factors suggests that treatment variation is based on opinion more so than evidence. Prognostic Level V. See Instructions for Authors for a complete description of levels of evidence.

Surgical Outcome of 2-Stage Management of Multiple Knee Ligament Injuries After Knee Dislocation

Introduction: JM, a 20-year-old male professional ice hockey player, presented with a 2-week history of lack of range of motion, weakness, and pain in his right knee, after a 2-year post-medical collateral ligament repair of the right knee and 3 year-post anterior cruciate ligament, posterior cruciate ligament and medial collateral ligament reconstruction of the right knee. Case Description: In the course of history taken, it was revealed that 5 months prior to admission the patient had been informed by a psychiatrist that he had sport-related anxiety. With an unremarkable psychiatric history prior to age 18, the competitive nature of his sports career in addition to financial pressure may have contributed to his sports-related anxiety. His examination findings were consistent with a diagnosis of complete tears of the right anterior cruciate ligament and posterior cruciate ligament along with grade III medial collateral ligament injury. Discussion: The biopsychosocial model was used to explicate JM's case. JM's current injuries prompted reconstruction of the anterior cruciate, posterior cruciate, and medial collateral ligaments. Psychologically, JM's sports-related anxiety is not a rare phenomenon as recent studies have discovered an increased risk of sports-related anxiety amongst young professional athletes. Sports-related anxiety, along with competitive trait anxiety, may be factors that contribute to sports injury occurrence. Other psychological stressors can add to sports-related or competitive trait anxiety, further increasing the risk of sports injury reoccurrence. Summary: JM was admitted for a right knee open medial collateral ligament repair with internal bracing, anterior cruciate ligament reconstruction, posterior cruciate ligament reconstruction, and platelet rich plasma injection. As part of a holistic patient-centered treatment plan, a referral to psychiatry was made to address JM's sports-related anxiety with the goal of decreasing future risk of sports injury. Patient's Consent Obtained: Yes

The incidence of posterior cruciate ligament (PCL) injuries in isolation is uncommon, but rather more regularly found with concurrent injuries, while medial-sided injuries are the most frequent among knee structures. The medial collateral ligament (MCL), spanning between the medial aspect of the femur and tibia, consists of a superficial medial (tibial) collateral ligament (sMCL) and a deep medial collateral ligament (dMCL) and provides stabilization from abnormal valgus motion and internal/external rotation. The PCL is composed of two bundles, the anterolateral bundle (ALB) and the posteromedial bundle (PMB), and is the strongest of the intra-articular knee ligaments. The PCL predominantly provides restraint to posterior tibial translation and external/internal tibial rotation. The most effective means in determining MCL injury is by severity of medial joint space gapping by valgus stress testing; PCL deficiency is evaluated relative to the posterior sag sign, the quadriceps active test, and the posterior drawer test. Injuries to either the PCL or MCL (Grade III) are suggestive for reconstruction. In the instance of concomitant injuries, tunnel convergence is frequently encountered among the tunnels drilled per structure, and coronal angulation of 40° for the MCL tunnel is beneficial for avoidance of the PCL tunnels. Surgical techniques using anatomic procedures for attachment sites are the most effective means for subsequently restoring kinematics of the knee joint, ultimately yielding greater outcome scores. Although single-bundle (SB) reconstructions are able to restore subjective outcomes, a high incidence of osteoarthritis (OA) progression is seen in patient outcomes. While double-bundle (DB) techniques show promising outcomes, long-term studies are needed to further define outcomes, as well as studies documenting treatment of concomitant MCL and PCL injuries.

Background: Knee joint is the most frequently injured joint as it is more superficial and susceptible. Previously, clinical examination was the sole method used to diagnose various knee disorders. Later, MRI and Arthroscopy were introduced and suggested by many surgeons. Aims and Objectives: This study was conducted to analyze the correlation between all three methods in the diagnosis of internal derangement of the knee in a tertiary care centre. Methodology: A hospital based cross-sectional study conducted at a tertiary care centre in Rajahmundry, India, between January 2017 to December 2017 among 124 patients aged 18-60 years and with internal derangement of the knee. Results: Among 124 patients, 111 (89.52%) were males and 13 (10.48%) females. Right side 84 (67.74%) was affected more than the left side 40 (32.26%). Mean age of the patients was 31 years with maximum number of them within 20-40 years. The most common mode of injury was road traffic accident followed by sports injuries. Clinically, ACL was the structure most commonly involved followed by medial meniscus, lateral meniscus, PCL, medial collateral ligament and lateral collateral ligament. MRI also revealed similar hierarchy in the involvement of structures, while arthroscopy showed that medial meniscus was most commonly involved followed by lateral meniscus, ACL, PCL, medial collateral ligament and lateral collateral ligament. With respect to correlation between procedures, medial meniscus, lateral meniscus, anterior cruciate ligament, posterior cruciate ligament and lateral collateral ligament injuries could be detected better by combined MRI and Arthroscopy, with Spearman’s rho being 0.671, 0.499, 0.477, 0.385 and 0.383 respectively and significant ‘P’ value (0.000). However, medial collateral ligament injuries could be detected better by combined clinical examination and MRI (Spearman’s rho 0.352 and ‘P’ 0.000). Conclusion: The sensitivity and specificity of MRI with Arthroscopy were higher for the diagnosis of internal derangements of knee, in comparison to the sensitivity and specificity of Clinical examination with Arthroscopy. However, Clinical examination is still dependable whenever possible. Keywords: Correlation, Clinical, MRI and Arthroscopy internal derangements of knee, India

The knee is the largest joint in the human body, making it particularly vulnerable to injury. Acute injury can result in ligamentous sprains and strains, dislocations/subluxations, and/or bony fractures either from direct trauma to the joint or indirect stress on previously healthy tissue. Most injuries to the knee involve the surrounding ligaments and/or tendons, with fractures composing an exceedingly small percentage of injuries. Prepubescent children are at greater risk for bony injury because before closure of the physis, tensile bone strength is less than that of ligament and tendon attachments. Once the physis closes, bone tensile strength exceeds that of ligaments/tendons, making ligamentous injury more common in postpubertal children. Although not the subject herein, it is important to remember that aside from traumatic injury, knee pain can be a manifestation of infectious, rheumatic, or oncologic pathology.Sprains or tears of the anterior or posterior cruciate ligament or the medial or lateral collateral ligament, meniscal tears, quadriceps tendon ruptures, patellar tendon ruptures, and hamstring strains are soft tissue injuries that can result from acute trauma to the knee.Anterior cruciate ligament tears are the most common ligamentous knee injury in children and skeletally immature adolescents. Typically, they occur during a sudden change in the rotational forces on the knee when the foot is fixed. Patients will describe a “pop,” or their knee “giving out,” and present with an acutely swollen knee with an effusion. Posterior cruciate ligament injuries are rare, resulting from direct force on the tibial tubercle, which pushes the tibia posteriorly relative to the femur. Medial and lateral collateral ligament injuries are more common in the skeletally mature patient and result from direct trauma to the contralateral side of the knee: trauma at the lateral aspect causes medial collateral ligament injury, and medial trauma affects the lateral collateral ligament. (A list of maneuvers to assess ligamentous injury appears in Table 1.)Meniscal tears result from sudden twisting of the leg while bearing weight. Patients, most commonly postpubertal, often describe their injury as a painful “locked knee” or “torn cartilage.” Quadriceps and patellar tendon ruptures occur in postpubertal children, typically older athletes, with an abrupt contraction of the quadriceps muscles, as when landing from a high jump or with a sudden change in direction at high velocity. As a result of the rupture, extension of the knee is limited.The muscles most affected by an acute injury to the knee are the hamstrings. Diagnosis of a hamstring strain is clinical, manifesting with significant swelling, local tenderness, and sometimes overlying ecchymosis.Dislocations of the knee joint in children are infrequent but serious limb-threatening injuries, occurring most frequently after physis closure. Typically, a significant traumatic force is involved, resulting in an overt deformity. Because the dislocation can shear the popliteal artery, which is anchored firmly to either end of the joint, and can also disrupt the peroneal nerve, evaluation of the limb’s neurovascular status is a crucial part of the physical examination.More common than dislocations of the knee joint, patellar dislocations occur with forceful contraction of the quadriceps while the lower leg is abducted. Classically, a “popping” sensation is described, and the patient has significant pain with the hip abducted, the knee held in the flexed position, and the patella laterally displaced. Because the diagnosis is based on history and examination, the dislocation can be reduced before obtaining radiographs by placing gentle pressure on the lateral aspect of the patella as the patient extends the knee. Postreduction radiographs should be obtained to rule out an associated avulsion or patella osteochondral fracture. If the history suggests patellar dislocation but the patella is in anatomical position, the dislocation could have self-reduced or subluxated. Such patients can have slight medial patella pain and are anxious during an attempt to push the patella laterally (apprehension test). If subluxation is suspected, radiographs should be obtained to look for an associated osteochondral fracture.Young children and other skeletally immature patients are the most likely to sustain Salter-Harris–type physeal fractures from direct trauma, as in contact sports or with motor vehicle accidents. Physeal fractures most commonly occur at the distal femoral epiphysis. Although rare, proximal tibial epiphyseal fractures can be limb-threatening because the popliteal artery lies just posterior to the tibial epiphysis. Sudden directional change can lead to tibial spine (intercondylar eminence) avulsion fractures in children 6 to 16 years of age because the tibial spine is not fully ossified and thus weaker than the surrounding ligaments. Tibial tuberosity avulsions occur most often in adolescents when the knee’s extensor mechanism is challenged during sudden acceleration or deceleration, typically with jumping. The tibial tubercle becomes swollen and painful, and the patient is unable to fully extend the knee or perform a straight leg raise. Patella fractures occur after direct trauma to the patella, such as falling on a flexed knee. They are rare in young children because the patella does not ossify until 3 to 6 years of age. Patellar avulsion fractures are more common, resulting from forceful contraction of the quadriceps. The patella is swollen, tender, and painful with extension. Osteochondral fractures can accompany patellar dislocation or injury to a ligament or meniscus. If left untreated, they can lead to permanent defects and osteoarthritis. Nearly all fractures of the knee are associated with swelling, significant pain, limited range of joint movement, and sometimes hemarthrosis.Subacute overuse injuries can present with chronic pain or acute worsening of pain. Table 2 lists the common overuse injuries.Evaluation of an injury to the knee includes an attempt to locate point tenderness, assessment of range of motion and ligamentous laxity, presence of an effusion, and neurovascular status of the lower leg. Laxity of the knee should be assessed in full extension and at 30° of flexion. The Ottawa Knee Rule is a highly sensitive clinical decision tool to help guide the need for knee radiographs in the setting of injury without a gross deformity. Anteroposterior and lateral radiographs of the knee (and a patellar view if indicated) should be obtained only if any of the following is present: patellar tenderness, tenderness at the head of the fibula, inability to flex to 90°, and inability to bear weight for 4 steps (regardless of limping), immediately with the injury and at presentation.Avulsion fractures of the patella pole (patellar sleeve fracture) can be missed easily on radiographs, and diagnosis may necessitate more advanced imaging. Hip imaging should also be considered after careful examination because hip pathology frequently causes referred knee pain. If knee radiographs do not reveal a fracture but the knee remains painful and swollen, damage to a ligament or meniscus is likely. Emergent orthopedic consultation is indicated if neurovascular compromise is suspected, puncture or lacerations raise concern for violation of joint integrity, with laxity of the knee in any direction, and with nonlateral patellar dislocations.Definitive management depends on the injury and ranges from conservative treatment with rest, ice, compression, and elevation to urgent operative intervention. Weightbearing status varies with the type of injury, and analgesia and ambulatory aides should be provided as necessary. If not indicated at the time of presentation, orthopedic follow-up should occur within 1 to 2 weeks if symptoms do not improve.Our authors note that aside from trauma, knee pain can result from infection or from rheumatoid and oncologic disorders. Another category in the differential diagnosis is joint laxity or hypermobility, which is, in fact, a relatively common cause of recurrent knee pain in children. Genetic disorders of connective tissue, such as Marfan and Ehlers-Danlos syndromes, as well as syndromes such as trisomy 21 and William syndrome, are associated with joint laxity, but much more common than any of these is the so-called benign joint hypermobility syndrome (BJHS). More frequent in girls than in boys, possibly related to estrogen effects, and especially among children of African or Asian descent, BJHS probably reflects excessive ligamentous laxity that allows range of motion beyond the normal. The knee joint is particularly susceptible, especially in the first decade after birth. Affected children may be described as “double jointed,” and their pain typically occurs late in a day marked by vigorous exercise. The painful joint(s) can show swelling, but not the redness and heat typical of inflammation. Recognition of BJHS, aided by the Beighton 9-point scale for hypermobility, can avoid unnecessary diagnostic evaluation and expedite appropriate management: reassurance with patient education, muscle-strengthening exercises, and pain control.

Objective To investigate the short-term clinical efficacy of arthroscopic reconstruction of posterior cruciate ligament (PCL) via double posteromedial portals. Methods A retrospective case series study was performed on the clinical data of 29 patients with PCL injury from January 2013 to January 2018 admitted to Xuancheng People's Hospital of Anhui province. There were 15 males and 14 females, with an average age of 49.6 years (range, 27-61 years). There were 13 patients with left knee injury and 16 patients with right knee injury. The combined injuries included five patients with medial meniscus tear, seven patients with lateral meniscus tear, one patient with medial collateral ligament injury, and two patients with lateral medial collateral ligament injury. The average duration from injury to surgery was 14.1 days ( range, 5-97 days). All patients received arthroscopic PCL reconstruction surgery using double posteromedial portals. The operation time and intraoperative blood loss were recorded. The posterior drawer test, reverse Lachman test, posterior translation, and Lysholm knee score scale were used to evaluate knee function preoperatively and 6 months after operation. The complications were recorded. Results All patients were followed up for 6-22 months (mean, 12 months). The operation time was (63.3±9.5) minutes, and the intraoperative blood loss was (48.9±22.8)ml. The posterior drawer tests and reverse Lachman tests of all patients turned to be negative 6 months after surgery. Preoperatively, the posterior translation and Lysholm score were (11.2±3.3)mm and (42.7±12.2)points, respectively. At 6 months postoperatively, the posterior translation and Lysholm score were (2.2±0.5)mm and (86.3±9.0)points, respectively (P<0.05). No complication such as infection and neurovascular injury occured. Conclusion The technique of arthroscopic PCL reconstruction surgery using double posteromedial portals has the advantages of good knee joint stability, less tibial posterior translation, and fast function recovery with satisfactory short-term efficacy. Key words: Knee injuries; Arthroscopy; Posterior cruciate ligament; Reconstruction