Expanding the clinical phenotype of RASopathies in 38 Turkish patients, including the rare LZTR1, RAF1, RIT1 variants, and large deletion in NF1.

RASopathies are a group of disorders caused by pathogenic variants in the genes encoding Ras/mitogen-activated protein kinase pathway and share overlapping clinical and molecular features. This study is aimed to describe the clinical and molecular features of 38 patients with RASopathies. Sanger or targeted next-generation sequencing of related genes and multiplex ligation-dependent-probe amplification analysis for NF1 were performed. The pathogenic variant detection rate was 94.4%. While PTPN11 was responsible for 50% of 18 patients with Noonan syndrome (NS), SOS1, LZTR1, RIT1, and RAF1 were responsible for the remaining 27.8%, 11.1%, 5.5%, and 5.5%, respectively. Three variants in LZTR1 were novel, of which two were identified in the compound heterozygous state in a patient with intellectual disability and hypertrophic cardiomyopathy, whereas the third variant was found in the heterozygous state in a patient with pulmonary stenosis and normal intelligence. We described pyloric stenosis, knee dislocation, and cleft palate in patients with SOS1, RIT1, and RAF1 variants, respectively, that was not previously reported. We detected a PTPN11 variant in three patients from same family with NS with multiple lentigines. BRAF and MAP2K2 variants were found in eight patients with Cardiofaciocutaneous syndrome. Two variants in HRAS were detected in two Costello syndrome patients, one with a mild and the other with a severe phenotype. While large NF1 deletions were identified in four Neurofibromatosis-NS patients with intellectual disability, intelligence was normal in one patient with missense variant. In conclusion, this study provided three novel variants in LZTR1 and expanded the clinical phenotype of rare RASopathies.

Is There a Disadvantage to Early Physical Therapy After Multiligament Surgery for Knee Dislocation? A Pilot Randomized Clinical Trial.

BACKGROUND: Multiligament knee injuries, though rare, can be profoundly disabling. Surgeons disagree about when to initiate rehabilitation after surgical reconstruction due to the conflicting priorities of postoperative stability and motion. QUESTIONS/PURPOSES: (1) Does early or late initiation of physical therapy after multiligament knee surgery result in fewer postoperative manipulations? (2) Does early versus late physical therapy compromise stability postoperatively? (3) Does early initiation of physical therapy result in improved patient-reported outcomes, as measured by the Multi-ligament Quality of Life (ML-QOL) score? METHODS: Between 2011 and 2016, 36 adults undergoing multiligament repair or reconstruction were prospectively enrolled in a randomized controlled trial and randomized 1:1 to either early rehabilitation or late rehabilitation after surgery. Eligibility included those with an injury to the posterior cruciate ligament (PCL) and at least one other ligament, as well as the ability to participate in early rehabilitation. Patients who were obtunded or unable to adhere to the protocols for other reasons were excluded. Early rehabilitation consisted of initiating a standardized physical therapy protocol on postoperative day 1 involving removal of the extension splint for quadriceps activation and ROM exercises. Late rehabilitation consisted of full-time immobilization in an extension splint for 3 weeks. Following this 3-week period, both groups engaged in the same standardized physical therapy protocol. All surgical reconstructions were performed at a single center by one of two fellowship-trained sports orthopaedic surgeons, and all involved allograft Achilles tendon PCL reconstruction. When possible, hamstring autograft was used for ACL and medial collateral ligament reconstructions, whereas lateral collateral ligament and posterolateral reconstruction was performed primarily with allograft. The primary outcome was the number of patients undergoing manipulation during the first 6 months. Additional outcomes added after trial registration were patient-reported quality of life scores (ML-QOL) at 1 year and an objective assessment of laxity through a physical examination and stress radiographs at 1 year. One patient from each group was not assessed for laxity or ROM at 1 year, and one patient from each group did not complete the ML-QOL questionnaires. No patient crossover was observed. RESULTS: With the numbers available, there was no difference in the use of knee manipulation during the first 6 months between the rehabilitation groups: 1 of 18 patients in the early group and 4 of 18 patients in the late group (p = 0.34). Similarly, there were no differences in knee ROM, stability, or patient-reported quality of life (ML-QOL) between the groups at 1 year. CONCLUSION: With the numbers available in this study, we were unable to demonstrate a difference between early and late knee rehabilitation with regard to knee stiffness, laxity, or patient-reported quality of life outcomes. The results of this small, randomized pilot study suggest a potential role for early rehabilitation after multiligament reconstruction for knee dislocation, which should be further explored in larger multi-institutional studies. LEVEL OF EVIDENCE: Level II, therapeutic study.

Dislocation of modern design rotating hinge total knee arthroplasty : case series and narrative review.

Knee dislocation is an infrequent complication after rotating hinge total knee arthroplasty (RHTKA). The aim of the present study was to describe our experience with dislocating RHTKA in a consecutive prospective large series, its occurrence rate, causative mechanisms and to perform a review of available literature. In total, six dislocations were observed in 303 RHTKA procedures (NexGen RHK, ZimmerBiomet, Warsaw, Indiana, US) at a mean of 10 (range, 2 - 24) months after surgery. This results in a 2% dislocation rate, which is lower than the 3.1% cumulative rate reported earlier in literature. Men and women were distributed equally, with a mean age of 56 years old. The indication for RHTKA among the six dislocations was revision in 4 cases and primary arthroplasty for the other 2 cases. Analysis revealed that the main mechanism of hinge dislocation was forced knee flexion with concomitant extensor mechanism insufficiency (4/6 cases). The second cause was unscrewing of the locking pin (2/6 cases). This is probably caused by the screw home mechanism that results in a counterclockwise torque -and therefore a loosening- effect on locking bolts, specifically in right-sided RHTKA. Obesity probably predisposes to hinge dislocation since 83% of patients in this series were obese (BMI, range 34 to 52). The findings of this study suggest that dislocation of RHTKA is a rare complication that could happen to obsese patients without an adequate extensor mechanism. Level of evidence : IV.

Poly-traumatic multi-ligament knee injuries: is the knee the limiting factor?

PURPOSE: Multi-ligament knee injuries (MLKI) from a high-velocity accident are rare but potentially devastating. This matched cohort analysis compares knee functional outcomes after multiple ligament reconstruction in poly-trauma patients to those that occurred in isolation. METHODS: Sixty-two patients with MLKI that occurred either as a component of polytrauma or had occurred in isolation were matched according to age, sex, and knee dislocation grade. Functional outcomes and knee physical examination were assessed at a 2-year follow-up. New Injury Severity Score (NISS) was calculated based on the poly-traumatic injury pattern. Risk factors for worse outcomes in the poly-trauma cohort were analyzed. RESULTS: The mean IKDC, Lysholm, and NISS scores in the polytrauma cohort were 57.2 ± 21.9, 62 ± 22, and 40.9 ± 20.4, respectively, at a mean of 67 months (range 24-220). The isolated knee injury group was followed for a mean of 74 months (range 24-266) with mean IKDC and Lysholm scores of 71.1 ± 26.5 and 78 ± 23, respectively. Patients in the control cohort had significantly higher IKDC (p = 0.01) and Lysholm scores, (p = 0.003). There were no major differences between the two groups in regards physical examination findings at final follow-up. None of the analyzed risk factors was predictive of poor outcome. CONCLUSION: When comparing knees with similar multi-ligament and neurovascular injury patterns, patients who sustained their injury as a result of poly-trauma demonstrated significantly lower functional scores following reconstruction. This is despite restoration of similar knee stability and range of motion. The functional outcomes following MLKI reconstruction in poly-traumatized patients are influenced by factors other than the knee including concomitant injuries and psychosocial factors. LEVEL OF EVIDENCE: Therapeutic Level III.

Traumatic Anterior Knee Dislocation with Popliteal Artery Injury: The Importance of a Prompt Diagnosis and Treatment to Obtain Lower Limb Salvage.

We report a case of traumatic anterior dislocation of the left knee in association with disruption of the soft tissues including knee ligaments, popliteal artery, and common peroneal nerve, resulting in lower limb acute ischemia. All components of this complex trauma were recognized and treated promptly. First, he was submitted to closed reduction of the dislocated knee under general anesthesia; right after he underwent superficial femoro-tibioperoneal trunk bypass using a reversed saphenous contralateral vein recurring to a posterior approach through a popliteal S-shaped incision; rehabilitation program was initiated early; a second and final reconstructive orthopedic operation was carried out in a different center. The present case is important in 2 aspects. First, it reports a very rare occurrence of simultaneous anterior dislocation of the knee associated with vascular insult and common peroneal nerve injury, which was rarely reported in the current literature; second, it highlights that with timely intervention and a team approach, excellent results could be achieved.

Effect of anteromedial and posterolateral anterior cruciate ligament bundles on resisting medial and lateral tibiofemoral compartment subluxations.

PURPOSE: This study analyzed the interaction of the anteromedial and posterolateral portions of the anterior cruciate ligament (ACL) in resisting medial and lateral tibiofemoral compartment subluxations under multiple loading conditions. METHODS: By use of a 6-df robotic simulator, 10 human cadaveric knees were tested in 3 states: intact ACL, partial ACL (loss of either the anteromedial bundle [AMB] or posterolateral bundle [PLB]), and deficient ACL. The testing profile involved anterior-posterior translation and internal-external rotation, as well as 3 pivot-shift loading conditions with varying internal rotation torque (1- or 5-Nm) and coupled anterior force (35- or 100-N). Digitization of anatomic landmarks provided tibiofemoral compartment translations and centers of tibial rotation. RESULTS: During pivot-shift testing (100-N anterior force, 1-Nm internal rotation torque, and 7-Nm valgus), the lateral and medial compartment anterior translation increased by a mean of 2.5 ± 0.8 mm (P = .016) and 3.4 ± 2.0 mm (P = .001), respectively, on AMB sectioning and 1.3 ± 0.9 mm (P = .329) and 0.6 ± 0.7 mm (P = .544), respectively, on PLB sectioning. Higher internal rotation torque (5 Nm v 1 Nm) on pivot-shift testing reduced central and medial anterior translation after ACL sectioning. There was no change in internal rotation on AMB or PLB sectioning. During the Lachman test (100-N), AMB and PLB sectioning increased central translation by 3.6 ± 1.6 mm (P = .001) and 0.7 ± 0.6 mm (P = .498), respectively. CONCLUSIONS: Both ACL bundles function synergistically in resisting medial and lateral compartment subluxations on the Lachman and pivot-shift tests. The AMB provided more restraint to anterior tibial translation during both tests as compared with the PLB. PLB sectioning produced no statistically significant change in anterior translation on the Lachman or pivot-shift test. Neither bundle contributed to resisting internal rotation. CLINICAL RELEVANCE: An ACL graft designed to duplicate the AMB would theoretically resist medial and lateral compartment anterior subluxations under multiple loading conditions. The PLB provides a secondary restraint at low flexion angles. Neither ACL bundle resists internal tibial rotation or allows a positive pivot-shift subluxation.

Does age predict outcome after multiligament knee reconstruction for the dislocated knee? 2- to 22-year follow-up.

PURPOSE: The purpose of this study is to determine whether age is a predictor of clinical and functional outcomes in patients who sustained a knee dislocation (KD) and underwent multiligament knee reconstruction. It was hypothesized that increasing age will negatively affect patient outcome. METHODS: In total, 125 multiligament knee injuries (MLKI) associated with KD were surgically reconstructed between 1992 and 2013 and evaluated with IKDC and Lysholm scores at a median follow-up of 5 (range 2-22) years. Patient demographics including age were then analysed with respect to IKDC and Lysholm scores using rank sums and pair-wise rank sums analysis for continuous variables and Chi-square analysis for categorical variables. RESULTS: In total, 125 patients (96 males and 29 females) with a median age of 31 (range 11-62) years at the time of surgery were included. At final follow-up, patients ≤30 years old compared to >30 years old obtained higher IKDC (73.3 vs. 61.9; p = 0.01) and Lysholm scores (76.9 vs. 68.5; p = 0.04). No confounding variables including gender, injury mechanism, injury pattern, injuries to the peroneal nerve, popliteal artery, meniscus, or cartilage accounted for differences in outcome scores between the two groups. CONCLUSION: Based on current available literature, this study represents the largest cohort with the longest follow-up reported on MLKI to date. At intermediate- to long-term follow-up, patients >30 years of age that undergo multiligament knee reconstruction for KD have inferior IKDC and Lysholm scores compared to those ≤30 years of age. However, successful multiligament knee reconstruction can still be obtained in this age group. LEVEL OF EVIDENCE: IV.

Superficial femoral artery transposition repair for traumatic popliteal rupture.

Closed dislocation of the knee with complete popliteal rupture is an uncommon injury. It requires prompt recognition and treatment to prevent limb loss. We describe a case of acute ischemia caused by complete knee dislocation with rupture of the popliteal artery that was successfully repaired with superficial femoral artery transposition. To the best of our knowledge, this is the first reported clinical experience of the use of an arterial autograft for revascularization of traumatic popliteal artery rupture.

Is peroneal nerve injury associated with worse function after knee dislocation?

BACKGROUND: Peroneal nerve palsy is a frequent and potentially disabling complication of multiligament knee dislocation, but little information exists on the degree to which patients recover motor or sensory function after this injury, and whether having this nerve injury--with or without complete recovery--is a predictor of inferior patient-reported outcome scores. QUESTIONS/PURPOSES: The purposes of this study were to (1) report on motor and sensory recovery as well as patient-reported outcomes scores of patients with peroneal nerve injury from multiligament knee dislocation; (2) compare those endpoints between patients who had partial versus complete nerve injuries; and (3) compare patient-reported outcomes among patients who sustained peroneal nerve injuries after knee dislocation with a matched cohort of multiligament knee injuries without nerve injury. METHODS: Thirty-two patients were identified, but five did not have 2-year followup and are excluded (16% lost to followup). Twenty-seven patients (24 male, three female) with peroneal nerve injury underwent multiligament knee reconstruction and were followed for 6.3 years (range, 2-18 years). Motor grades were assessed by examination and outcomes by International Knee Documentation Committee (IKDC) and Lysholm scores. Retrospectively, patients were divided into complete (n = 9) and partial nerve palsy (n = 18). Treatment for complete nerve palsy included an ankle-foot orthosis for all patients, nonoperative (one), neurolysis (two), tendon transfer (three), nerve transfer (one), and combined nerve/tendon transfer (one). Treatment for partial nerve palsy included nonoperative (12), neurolysis (four), nerve transfer (one), and combined nerve/tendon transfer (one). Furthermore, patients without nerve injury were matched by Schenck classification, age, and sex. Data were analyzed using univariate and multivariate models. RESULTS: Overall, 18 patients (69%) regained antigravity ankle dorsiflexion after treatment (three complete nerve palsy [38%] versus 15 partial nerve palsy [83%]; p = 0.06). One patient with complete nerve palsy (13%) and 13 patients with partial nerve palsy (72%) regained antigravity extensor hallucis longus strength (p = 0.01). IKDC and Lysholm scores were similar between complete nerve palsy and partial nerve palsy groups. After controlling for confounding variables such as patient age, body mass index, injury interval to surgery, mechanism of injury, bicruciate injury, and popliteal artery injury status, there was no difference between patients with peroneal nerve injury and those without on Lysholm or IKDC scores. CONCLUSIONS: With multiligament knee dislocation and associated peroneal nerve injury, patients with partial nerve injury are more likely to regain antigravity strength when compared with those with a complete nerve injury, but their overall function may not improve. After controlling for confounding variables in a multivariate model, there was no difference in Lysholm or IKDC scores between patients with peroneal nerve injury and those without. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Long-term followup of surgically treated knee dislocations: stability restored, but arthritis is common.

BACKGROUND: Surgical treatment of knee dislocations is intended to correct the anatomic injury and restore knee stability and patient function. Several studies have shown successful results with surgical treatment of knee dislocations with up to 10 years of followup, but longer-term studies are uncommon. QUESTIONS/PURPOSES: We evaluated patients treated surgically for knee dislocations at 10-year followup to assess (1) knee stability; (2) return to preinjury level of function; (3) development of arthrosis; and (4) range of motion (ROM) loss. METHODS: This study was a retrospective review of 127 combined PCL, ACL, and medial and/or lateral side reconstructions performed by a single surgeon (GCF) between 1990 and 2008. Of these, 44 were available for clinical and functional evaluation (35%) at a minimum 5-year followup. Inclusion criteria were combined PCL/ACL plus medial and/or lateral side reconstruction. Evaluation methods included arthrometer measurements, stress radiography, knee ligament rating and activity scales (Lysholm and Tegner), plain radiographs with osteoarthritic assessment, and physical examination. RESULTS: Of the 44 patients, there were nine ACL/PCL medial, 22 ACL/PCL lateral, and 13 ACL/PCL mediolateral reconstructions. Followup was at a minimum of 5 years (mean, 10 years; range, 5-22 years). The mean age at the time of injury was 31 years with a range of 13 to 65 years. The mean arthrometer-measured side-to-side differences were as follows: PCL screen, 1.9 mm; corrected posterior, 2.4 mm; corrected anterior, 0.8 mm; and anterior displacement at 30° of knee flexion, 1.7 mm. Stress radiographic measurements at 90° of knee flexion revealed a mean side-to-side difference of 1.9 mm. Mean Lysholm, and Tegner scores were 84 of 100 and 4.1 of 9, respectively. Ninety-three percent (41 of 44) of patients returned to their preinjury level of activity or one Tegner grade lower. Ten of the 44 knees (23%) developed degenerative joint disease. The mean flexion loss was 12.5°, and flexion contractures were not seen in any of the patients. CONCLUSIONS: We found that a high proportion of patients treated for these severe injuries achieved static and functional stability, allowing the return to physically demanding work and recreational activities, but that nearly one-fourth of them will develop arthritis at a mean of 10 years. We cannot extrapolate our results to an elite athlete population, but our results probably apply well to working class populations. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Posterior tibial tendon transfer improves function for foot drop after knee dislocation.

BACKGROUND: Knee dislocation may be associated with an injury to the common peroneal nerve with a subsequent foot drop. Previous studies have demonstrated good functional results after posterior tibial tendon transfer in patients with foot drop. No studies, to our knowledge, have focused exclusively on knee dislocation as the cause of common peroneal nerve injury leading to foot drop. QUESTIONS/PURPOSES: We determined the percentage of patients developing common peroneal nerve paresis after knee dislocation, the symptom improvement rate in these patients, and patient-reported outcomes (American Orthopaedic Foot and Ankle Society [AOFAS] ankle-hindfoot score), ankle dorsiflexion strength, and ROM in patients with no symptom improvement treated with posterior tibial tendon transfer. METHODS: Two hundred forty-seven patients with knee dislocation, defined as an injury to both the ACL and PCL with an additional injury to the lateral and/or medial ligaments (Schenck Classification II to IV), were registered in a single institution's database between 1996 and 2011. The database was queried for the frequency of documented injuries to the common peroneal nerve and, among those, the frequency of spontaneous resolution after this injury. Patients demonstrating no active dorsiflexion 12 months after injury generally were offered posterior tibial tendon transfer. Postoperatively, patients were evaluated for AOFAS score, ankle dorsiflexion strength, and ROM. RESULTS: Forty-three patients (17%) had a common peroneal nerve paresis at admission. At 1-year followup, 15 of 43 patients (35%) had experienced symptom improvement. One patient experienced spontaneous improvement later than 1 year after injury. One patient was lost to followup. A below-knee amputation was performed in one patient due to the initial trauma. Seven patients were satisfied with their function using a brace or had medical contraindications to surgical treatment, while four patients refused the proposed operation with a tendon transfer, leaving 14 patients treated with posterior tibial tendon transfer. In the 12 patients available for evaluation, mean AOFAS score was 91 of 100. Mean (± SD) dorsiflexion strength was 118 (± 55) Nm on the operated side and 284 (± 94) Nm on the unaffected side (p < 0.001). Mean ROM was 67° (± 15°) on the operated side and 93° (± 14°) on the unaffected side (p < 0.001). CONCLUSIONS: Based on these findings, we recommend posterior tibial tendon transfer for treatment of foot drop that persists at least 1 year after knee dislocation. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Dynamic KINE-MRI in patellofemoral instability in adolescents.

PURPOSE: The impact of kinematic MRI (KINE-MRI) in the patellofemoral instability and anterior knee pain of the adolescents is rarely reported. Our special interest was to evaluate the patellofemoral joint biomechanics with KINE-MRI in adolescents with affected and unaffected knees in a case-control study. METHODS: KINE-MRI was performed in 29 adolescents (affected knee group, n = 29 and unaffected knee group, n = 26) aged 11-16 years with unilateral patellofemoral instability. For the control group, we enrolled ten healthy age- and sex-matched volunteers (healthy knee group, n = 19). The study parameters, bisect offset, lateral patellar displacement, patellar tilt angle, sulcus angle and Insall-Salvati ratio at 0, 10, 20 and 30° of flexion-extension, were measured for the affected knee patients (n = 29), unaffected knee patients (n = 26) and the healthy knee subjects (n = 19). RESULTS: The affected knee and the healthy knee subjects had a significant difference in the bisect offset ratio, lateral patellar displacement test and patellar tilt angle test. In these parameters, the difference between the affected knee patients and the healthy knee subjects progressively increased towards the full extension of the knee. In the affected knee and unaffected knee patients, bisect offset ratio at 0° ranged between 0.50 and 1.20 in both groups, whereas the bisect offset ratio in the healthy knee subjects ranged between 0.33 and 0.75 (p < 0.001). At the 0°, the lateral patellar displacement test ranged between 0 and 10 mm in the affected knee patients and between 0 and 35 mm in the unaffected knee patients, whereas the lateral displacement test ranged between 0 and 5 mm in the healthy knee subjects (p = 0.003). Patellar tilt angle test ranged between -30 and 20° in the affected knee patients and between -30 and 24° in the unaffected knee patients, and in the healthy knee subjects, the patellar tilt angle test ranged between 10 and 24° (p < 0.001). CONCLUSIONS: The KINE-MRI was able to detect significant differences in patellofemoral joint kinematics between the patients and the healthy subjects. A new finding with clinical relevance in our work is that the unaffected knee is very similar to the dislocated knee in adolescents and this should be taken in account in rehabilitation of patients. LEVEL OF EVIDENCE: II.

Knee dislocations: is reconstruction of the posterior cruciate ligament crucial?

The purpose of the present study was to investigate our 6-10 year results for knee dislocations with posterolateral corner (PLC) involvement, where a primary repair was performed laterally, the anterior cruciate ligament (ACL) reconstructed, but the posterior cruciate ligament (PCL) was left without surgery. Four consecutive patients with knee dislocation with complete rupture of the ACL, the PCL and the PLC were operated on by the same surgeon with similar technique. There were no other major injuries. We used strict inclusion criteria to get as homogenous population as possible. The ACL injuries were reconstructed and the PLC primary repaired, but the PCLs were not reconstructed. After 1-5 years, KOOS, EQ5D and work performance were recorded. Five years later these scores were repeated, with addition of the Lysholms and Tegners, standing radiographs and posterior stress radiographs. All patients were working fulltime from 1 year postoperatively onwards. One patient had returned to high-level sports activities, but the other three had lowered their activity. One patient had slight joint space narrowing at standing radiographs, but the other three appeared normal. All patients had increased posterior laxity with stress radiographs, and the tibiae were positioned more posterior with standard standing radiographs. Patients with knee dislocations where the PCL had not been reconstructed performed fairly good after more than 6 years. This study does not show that leaving the PCL in a dislocated knee is better than reconstructing it, but it may be an acceptable option.

Late presentation of congenital dislocation of the knee: a case report.

Congenital dislocation of the knee is a rare disorder. Late presentation of congenital dislocation of the knee at an older age is a therapeutic challenge. A 12-year-old girl presented to us with congenital dislocation of the knee and with complaints of limp, short limb, and pain on weight bearing. Two-stage surgery was performed with quadricepsplasty followed by gradual distraction in the first stage and repeat quadricepsplasty, anterior capsular release, and open reduction in the second stage. The result was fair to good with a stable and painless knee on walking.

Surgical technique: articulated external fixator for treatment of complex knee dislocation.

BACKGROUND: Knee dislocation is a severe but relatively uncommon injury caused by violent trauma that can result in long-term complications, such as arthrofibrosis, stiffness, instability, and pain. Perhaps owing in part to its rarity, treatment of this injury is controversial. We therefore describe a treatment approach for these complex cases involving a novel dynamic knee external fixator. DESCRIPTION OF TECHNIQUE: We performed open PCL reconstruction when possible and/or repair of other associated lesions. At the end of the surgical procedure, the surgeon applied an external fixator that reproduced normal knee kinematics, allowing early motion exercises and reducing the risk of joint stiffness while protecting the bony and soft tissue structures involved in the repair during the first healing phase. PATIENTS AND METHODS: We retrospectively reviewed eight patients treated with this approach, four of whom had the PCL reconstructed and four of whom had only associated injuries reconstructed. We evaluated all patients with clinical scores (subjective International Knee Documentation Committee form, Lysholm score, and Tegner level), physical examination (objective International Knee Documentation Committee form), and KT-1000™ arthrometer for AP laxity. Minimum followup was 10 months (mean, 26 months; range, 10-45 months). RESULTS: One patient had manipulation under anesthesia. The median Lysholm score was 76, Tegner level was 4, and subjective International Knee Documentation Committee was 73. All patients recovered to their preinjury work activity, except one unemployed patient. Stability was normal or nearly normal in five patients; the mean side-to-side difference in AP displacement with manual maximum force was 2.9 mm. CONCLUSIONS: This approach with an external fixator allowed staged reconstruction and early motion and provided reasonable stability, ROM, and activity level at followup in patients with complex injuries. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Risk factors for peroneal nerve injury and recovery in knee dislocation.

BACKGROUND: Acute knee dislocation is rare but has a high rate of associated neurovascular injuries and potentially limb-threatening complications. These include the substantial morbidity associated with peroneal nerve injury: neuropathic pain, decreased mobility, and considerably reduced function, which not only impairs patient function but complicates treatment. QUESTIONS/PURPOSES: We therefore identified and quantified the risks associated with specific factors for peroneal nerve injury and recovery in patients with knee dislocations. PATIENTS AND METHODS: We retrospectively reviewed the charts of 26 patients, from among a cohort of all 91 knee dislocations, with a peroneal nerve palsy over a 5-year period. We then used univariable and multivariable statistics to identify risk factors predicting peroneal nerve injury and recovery. RESULTS: Gender (odds ratio, 5.47), body mass index (odds ratio, 1.14), and fibular head fracture (odds ratio, 4.77) were associated with peroneal nerve injury. Only younger age was associated with peroneal nerve recovery. CONCLUSIONS: Knowledge of the risk factors for peroneal nerve injury and the predictors of recovery in knee dislocation allows the treating surgeon to have a better understanding of the nature of the neurologic injury and modify management based on the anticipated return of nerve function. LEVEL OF EVIDENCE: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Posteromedial corner injury in knee dislocations.

Surgeons are often faced with very limited data available to make informed decisions regarding the appropriate treatment of patients with posteromedial corner (PMC) injuries of the knee. This study compared the outcomes of surgical repair versus reconstruction in knee dislocation patients who have sustained injury to the PMC of the knee. Senior author treated 113 consecutive knee dislocations with 115 PMC injuries over 7 years. A total of 71 knee dislocation patients with 73 PMC tears qualified for the study and were followed for a mean of 43 months. Patients who had a PMC repair were assigned to treatment Group A. Group B included patients who had autograft reconstruction of the PMC. Patients who had an allograft PMC were assigned to Group C. A total of 25 patients had a repair, with 5 failures (20%), whereas 48 patients had reconstruction of the PMC with 2 failures (4%). There was a significant difference between the failure rate of PMC repairs and PMC reconstructions. Reconstruction of the PMC using a technique that reestablishes the critical triangle of the medial collateral ligament, the posterior oblique ligament, and the semitendinosus yielded better stability than repair in patients with a knee dislocation that included PMC instability.

Posterior dislocation in total knee replacement: a price for deep flexion?

INTRODUCTION: Post-cam dislocation in TKA is a rare complication after posterior stabilized TKA. PURPOSE: Four cases of posterior dislocation of the tibia relative to the femur are described in one current posterior stabilized design. CONCLUSION: Specific design features in one contemporary high flexion TKA design contribute to high dislocation rates.

Evaluation of reconstructive surgery using artificial ligaments in 71 acute knee dislocations.

This retrospective study assessed the results of 71 patients with knee dislocations who underwent acute combined repair and reconstruction using Ligament Advancement Reinforcement System (LARS) artificial ligaments between June 1996 and May 2008 with a follow-up between two and eight years. The outcome measures used were the Lysholm score, the International Knee Documentation Committee form (IKDC 2000), the Tegner activity level score, the Meyers ratings, Telos stress radiography, range of motion and clinical knee stability testing. When comparing high- versus low-energy dislocations and knee dislocation (KD) II/III versus KD IV injuries, a better Lysholm score for the knee dislocation (KD) II/III group was found compared with the KD IV group. The subjective and objective findings from our study are satisfactory and comparable with the results of other studies of knee dislocations. Our findings suggest that with a mean follow-up of 54 months, acute combined repair and reconstruction with LARS ligaments is a valid alternative for treating knee dislocations.