Results of isolated posterolateral corner reconstruction

BACKGROUND: Isolated posterolateral corner (PLC) tears are relatively rare events. Various surgical techniques to treat posterolateral knee instability have been described; because surgical results are linked to cruciate reconstructions it has been difficult to date to define whether one surgical procedure has better prognosis than another. The goal of this study is to determine the clinical outcome of PLC reconstruction following fibular-based technique. MATERIALS AND METHODS: We retrospectively evaluated a case series of patients who received isolated PLC reconstruction between March 2005 and January 2007. Ten patients were surgically treated for isolated injuries and were available for follow-up; average patient age was 27.4 years (range 16-47 years). All patients were treated following the fibular-based technique: double femoral tunnel was performed in six patients, while in the remaining four patients, the reconstruction of the PLC was performed with a single femoral tunnel. Six patients had semitendinosus allograft and four had semitendinosus autograft. All patients had the same evaluation and the same rehabilitation protocol. RESULTS: Mean follow-up was 27.5 months (range 18-40 months). Mean range of motion (ROM) was 143.5 degrees for flexion (range 135-150 degrees) and 0.5 degrees for extension (range 0-3 degrees). Three patients showed 1+ on varus stress test, while on Dial test another three patients showed 10 degrees reduction of external rotation compared with contralateral knee. The average Lysholm score was 94 points (range 83-100), and the mean International Knee Documentation Committee (IKDC) subjective result was 88.48 (range 74-96.5). Based on Lysholm score, the results were excellent in eight knees and good in two knees. On IKDC evaluation, two patients were grade A and eight were grade B. No significant difference in clinical results was observed between single and double femoral tunnel. CONCLUSION: Fibular-based technique showed good results in terms of clinical outcome, restoring varus and rotation stability of knees in treatment of chronic isolated PLC injury

Assessment of correlation between knee notch width index and the three-dimensional notch volume

This study was done to determine whether there is a correlation between the notch volume and the notch width index (NWI) as measured on the three most frequently used radiographic views: the Holmblad 45°, Holmblad 70°, and Rosenberg view. The notch volume of 20 cadaveric knees was measured using Computed Tomography (CT). The Holmblad 45°, Holmblad 70°, and Rosenberg notch view radiographs were digitally re-created from the CT scans for each specimen, and the NWI was measured by two observers. The Pearson correlation coefficient between the NWI and notch volume was calculated, as well as between the three views. An independent t test was performed to determine the difference in NWI and notch volume between male and female specimens. The reliability for each view was also determined. There was no correlation between the NWI as measured on the Holmblad 45°, Holmblad 70°, or Rosenberg view and the notch volume. All three radiographic views proved reliable, but showed only a moderate correlation with each other. Men had larger notch volumes than women, but there was no difference in NWI. A knee with a small intercondylar notch is often considered an increased risk for ACL rupture. The NWI is a frequently used two-dimensional method to determine notch size. However, in the present study, this index was not positively correlated with the overall volume of the notch. Based on the results of the current study, the authors would advice to use caution when using notch view radiographs in a clinical setting to predict risk of ACL rupture

Medial patellofemoral ligament injury patterns and associated pathology in lateral patella dislocation: an MRI study

BACKGROUND: Lateral Patella dislocations are common injuries seen in the active and young adult populations. Our study focus was to evaluate medial patellofemoral ligament (MPFL) injury patterns and associated knee pathology using Magnetic Resonance Imaging studies. METHODS: MRI studies taken at one imaging site between January, 2007 to January, 2008 with the final diagnosis of patella dislocation were screened for this study. Of the 324 cases that were found, 195 patients with lateral patellar dislocation traumatic enough to cause bone bruises on the lateral femoral trochlea and the medial facet of the patella were selected for this study. The MRI images were reviewed by three independent observers for location and type of MPFL injury, osteochondral defects, loose bodies, MCL and meniscus tears. The data was analyzed as a single cohort and by gender. RESULTS: This study consisted of 127 males and 68 females; mean age of 23 yrs. Tear of the MPFL at the patellar attachment occurred in 93/195 knees (47%), at the femoral attachment in 50/195 knees (26%), and at both the femoral and patella attachment sites in 26/195 knees (13%). Attenuation of the MPFL without rupture occurred in 26/195 knees (13%). Associated findings included loose bodies in 23/195 (13%), meniscus tears 41/195 (21%), patella avulsion/fracture in 14/195 (7%), medial collateral ligament sprains/tears in 37/195 (19%) and osteochondral lesions in 96/195 knees (49%). Statistical analysis showed females had significantly more associated meniscus tears than the males (27% vs. 17%, p = 0.04). Although not statistically significant, osteochondral lesions were seen more in male patients with acute patella dislocation (52% vs. 42%, p = 0.08). CONCLUSION: Patients who present with lateral patella dislocation with the classic bone bruise pattern seen on MRI will likely rupture the MPFL at the patellar side. Females are more likely to have an associated meniscal tear than males; however, more males have underlying osteochondral lesions. Given the high percentage of associated pathology, we recommend a MRI of the knee in all patients who present with acute patella dislocation

Isometry of medial collateral ligament reconstruction

The purpose of this study was to determine the femoral and tibial fixation sites that would result in the most isometric MCL reconstruction technique. Seven cadaveric knees were used in this study. A navigation system was utilized to determine graft isometry continuously from 0º to 90º. Five points on the medial side of the femur and four on the tibia were tested. A graft positioned in the center of the MCL femoral attachment (FC) and attached in the center of the superficial MCL attachment on the tibia led to the best isometry (2.7 ± 1.1 mm). Movement of the origin superiorly only 4 mm (FS) led to graft excursion of greater than 10 mm (P < 0.01). MCL reconstruction performed with the origin of the MCL within the femoral footprint and the insertion in tibial footprint of the superficial MCL results in the least graft excursion when the knee is cycled between 0º and 90º. Although the MCL often heals without surgical intervention, surgical reconstruction is occasionally in Grade III MCL and combined ligamentous injuries to the knee. This study demonstrates the optimal position of the MCL reconstruction to reproduce the kinematics of the native knee

Role of high tibial osteotomy in chronic injuries of posterior cruciate ligament and posterolateral corner

High tibial osteotomy (HTO) is a surgical procedure used to change the mechanical weight-bearing axis and alter the loads carried through the knee. Conventional indications for HTO are medial compartment osteoarthritis and varus malalignment of the knee causing pain and dysfunction. Traditionally, knee instability associated with varus thrust has been considered a contraindication. However, today the indications include patients with chronic ligament deficiencies and malalignment, because an HTO procedure can change not only the coronal but also the sagittal plane of the knee. The sagittal plane has generally been ignored in HTO literature, but its modification has a significant impact on biomechanics and joint stability. Indeed, decreased posterior tibial slope causes posterior tibia translation and helps the anterior cruciate ligament (ACL)-deficient knee. Vice versa, increased tibial slope causes anterior tibia translation and helps the posterior cruciate ligament (PCL)-deficient knee. A review of literature shows that soft tissue procedures alone are often unsatisfactory for chronic posterior instability if alignment is not corrected. Since limb alignment is the most important factor to consider in lower limb reconstructive surgery, diagnosis and treatment of limb malalignment should not be ignored in management of chronic ligamentous instabilities. This paper reviews the effects of chronic posterior instability and tibial slope alteration on knee and soft tissues, in addition to planning and surgical technique for chronic posterior and posterolateral instability with HTO

Biologic Treatments for Sports Injuries II Think Tank-Current Concepts, Future Research, and Barriers to Advancement, Part 2:Rotator Cuff

Rotator cuff tears are common and result in considerable morbidity. Tears within the tendon substance or at its insertion into the humeral head represent a considerable clinical challenge because of the hostile local environment that precludes healing. Tears often progress without intervention, and current surgical treatments are inadequate. Although surgical implants, instrumentation, and techniques have improved, healing rates have not improved, and a high failure rate remains for large and massive rotator cuff tears. The use of biologic adjuvants that contribute to a regenerative microenvironment have great potential for improving healing rates and function after surgery. This article presents a review of current and emerging biologic approaches to augment rotator cuff tendon and muscle regeneration focusing on the scientific rationale, preclinical, and clinical evidence for efficacy, areas for future research, and current barriers to advancement and implementation

Derivation of Chondrogenically-Committed Cells from Human Embryonic Cells for Cartilage Tissue Regeneration

Background: Heterogeneous and uncontrolled differentiation of human embryonic stem cells (hESCs) in embryoid bodies (EBs) limits the potential use of hESCs for cell-based therapies. More efficient strategies are needed for the commitment and differentiation of hESCs to produce a homogeneous population of specific cell types for tissue regeneration applications. Methodology/Principal Findings: We report here that significant chondrocytic commitment of feeder-free cultured human embryonic stem cells (FF-hESCs), as determined by gene expression and immunostaining analysis, was induced by coculture with primary chondrocytes. Furthermore, a dynamic expression profile of chondrocyte-specific genes was observed during monolayer expansion of the chondrogenically-committed cells. Chondrogenically-committed cells synergistically responded to transforming growth factor-b1 (TGF-b1) and b1-integrin activating antibody by increasing tissue mass in pellet culture. In addition, when encapsulated in hydrogels, these cells formed cartilage tissue both in vitro and in vivo. In contrast, the absence of chondrocyte co-culture did not result in an expandable cell population from FF-hESCs. Conclusions/Significance: The direct chondrocytic commitment of FF-hESCs can be induced by morphogenetic factor