MH Residency- Knee

Background Understanding hamstring muscle activation patterns in resistance training exercises may have implications for the design of strength training and injury prevention programs. Unfortunately, surface electromyography studies have reported conflicting results regarding hamstring muscle activation patterns in women. Objectives To determine the spatial patterns of hamstring muscle activity during the 45° hip extension and Nordic hamstring exercises in women using functional magnetic resonance imaging (fMRI)...

The number of posterolateral corner (PLC) injury patients has risen owing to the increased motor vehicle accidents and sports activities. Careful examination is required because this injury is easy to overlook and may lead to chronic instability. The purpose of this article is to review the anatomy, biomechanics, diagnosis, classification and, treatment of PLC injuries and summarize the recent literatures regarding the treatment outcomes.

PURPOSE: To determine the radiographic landmarks of the anterolateral ligament (ALL) on the femur and tibia to assist in intraoperative graft placement during ALL reconstruction. METHODS: The footprints of the ALL, fibular collateral ligament (FCL), popliteus insertion, lateral gastrocnemius insertion, and Gerdy's tubercle were isolated and centrally marked with tantalum beads in thirteen fresh-frozen cadaveric knees. Measurements were taken from the true lateral fluoroscopic images...

OBJECTIVE: This article reviews current concepts of knee replacement. Features of traditional and new prosthetic designs, materials, and surgical techniques are discussed. Normal and abnormal postoperative imaging findings are illustrated. Complications are reviewed and related to the current understanding about how and why these failures occur. CONCLUSION: It is well known that after knee replacement, patients with complications may be asymptomatic, and, for this reason, assessment of postoperative imaging is important...

A 65-year-old woman presented with pain in both knees. She had received a diagnosis of osteoarthritis of the knee previously and had been treated with analgesic agents and nonsteroidal antiinflammatory drugs. In addition, she was treated intermittently with intraarticular injection of a..

PURPOSE: To evaluate weight-bearing and joint symmetry during the double-leg squat exercise at baseline and after fatigue in patients who have undergone anterior cruciate ligament reconstruction (ACLR) compared to uninjured controls. METHODS: Ten males who had returned to sport after primary ACLR participated along with ten uninjured male controls. Lower limb kinematic, kinetic and ground reaction force (GRF) data were collected during double-leg squats at baseline and after a generalised fatigue protocol...

No abstract text is available yet for this article.

PURPOSE: To investigate the effect of different loads of knee extensor open kinetic chain resistance training on anterior knee laxity and function in the ACL-injured (ACLI) knee. METHODS: Fifty-eight ACLI subjects were randomised to one of three (12-week duration) training groups. The STAND group trained according to a standardised rehabilitation protocol. Subjects in the LOW and HIGH group trained as did the STAND group but with the addition of seated knee extensor open kinetic chain resistance training at loads of 2 sets of 20 repetition maximum (RM) and 20 sets of 2RM, respectively...

BACKGROUND: Meniscal allograft transplantation (MAT) was developed as a means of treating the symptoms of compartmental overload after meniscectomy. Despite more than 20 years of research in this field, many controversies still exist regarding meniscal transplantation. PURPOSE: The aims of this study were to assess (1) the quality of the published studies on MAT; (2) the indications for this type of surgery; (3) the methods used for preservation, sizing, and fixation of the allograft; and (4) the clinical and radiographic outcomes of this procedure and its role in preventing osteoarthritis...

PURPOSE: The principal aim of this study was to report the outcomes of medial patellofemoral ligament (MPFL) reconstruction, used as either an isolated procedure or in combination with another stabilization procedure, for the primary treatment of recurrent patellar instability. METHODS: Between 2007 and 2012, 45 patients with recurrent patellar instability and no prior stabilization surgery had an MPFL reconstruction by a single surgeon, either as an isolated procedure or in combination with another stabilization procedure...

OBJECTIVE: To determine range of motion (ROM), postural alignment, and dynamic motion differences between those with and without medial knee displacement (MKD) during the overhead squat (OHS). We hypothesized those with MKD would have restricted ROM, differing postural alignment, and poorer quality dynamic motion than those without MKD. DESIGN: Observational. SETTING: University Research Laboratory. PARTICIPANTS: Ninety-seven healthy recreationally active college-aged individuals...

Osteochondritis dissecans (OCD) can affect both adults and children, however the imaging characteristics and significance of imaging findings can differ in the juvenile subset with open physes. Radiography and magnetic resonance imaging (MRI) are the primary modalities used to aid in diagnosis, to define a treatment plan, to monitor progress, to assess surgical intervention, and to identify postoperative complications. Newer imaging techniques under continuous development may improve the accuracy of MRI for diagnosis and staging of OCD, and eventually may help to predict the durability of tissue-engineered constructs and cartilage repair...

Multiple systems for classifying osteochondritis dissecans (OCD) of the knee have been reported. These existing classification systems have some similar characteristics, such as stable lesion/intact articular cartilage and presence of a loose body. However, variations are found in the number of stages and specific lesion characteristics assessed. Currently, no system has been universally accepted. A future classification system should be developed that reconciles the discrepancies among the current systems and provides a clear, consistent, and reliable method for classifying OCD lesions of the knee during arthroscopy...

Although several hypotheses have been described to explain the cause of osteochondritis dissecans, no single hypothesis has been accepted in the orthopedic community. Given its increased incidence among athletes, most in the sports medicine community agree that repetitive microtrauma plays at least some role in its development. Knowledge regarding the epidemiology and pathoanatomy of osteochondritis dissecans has helped the understanding of osteochondritis dissecans; however, much is still to be learned about this condition and its cause...

No abstract text is available yet for this article.

The hamstring muscles were analyzed anatomically and physiologically to clarify the specific reasons for the incidence of muscle strain of the hamstrings. For the anatomical study, hamstring muscles of 13 embalmed cadavers were dissected. For the physiological study, the knee flexor torque and surface electromyographic (EMG) signals were measured during isometric contraction of hamstring muscles in 10 healthy adults. The biceps femoris muscle long head (BF-L) and semimembranosus muscle (SM) had hemi-pennate architecture and their fiber length per total muscle length (FL/TML) was smaller than that of semtendinosus muscle (ST) and biceps femoris muscle short head (BF-S) with other architecture...

Patellofemoral pain syndrome (PFPS) is the most common cause of knee pain in the outpatient setting. It is caused by imbalances in the forces controlling patellar tracking during knee flexion and extension, particularly with overloading of the joint. Risk factors include overuse, trauma, muscle dysfunction, tight lateral restraints, patellar hypermobility, and poor quadriceps flexibility. Typical symptoms include pain behind or around the patella that is increased with running and activities that involve knee flexion...

BACKGROUND: Many patients report symptomatic relief after undergoing arthroscopy of the knee for osteoarthritis, but it is unclear how the procedure achieves this result. We conducted a randomized, placebo-controlled trial to evaluate the efficacy of arthroscopy for osteoarthritis of the knee. METHODS: A total of 180 patients with osteoarthritis of the knee were randomly assigned to receive arthroscopic débridement, arthroscopic lavage, or placebo surgery. Patients in the placebo group received skin incisions and underwent a simulated débridement without insertion of the arthroscope...