Injuries to the quadriceps muscle group are common in athletes performing high-speed running and kicking sports. The complex anatomy of the rectus femoris puts it at greatest risk of injury. There is variability in prognosis in the literature, with reinjury rates as high as 67% in the severe graded proximal tear. Studies have highlighted that athletes can reinjure after nonoperative management, and some benefit may be derived from surgical repair to restore function and return to sport (RTS). This injury is potentially career-threatening in the elite-level athlete, and we aim to highlight the key recent literature on interventions to restore strength and function to allow early RTS while reducing the risk of injury recurrence. This article reviews the optimal diagnostic strategies and classification of quadriceps injuries. We highlight the unique anatomy of each injury on MRI and the outcomes of both nonoperative and operative treatment, providing an evidence-based management framework for athletes.

Cite this article: Bone Joint J 2023;105-B(12):1244–1251.

The October 2023 Research Roundup. 360. looks at: Gut microbiota in high-risk individuals for rheumatoid arthritis associated with disturbed metabolome and initiates arthritis by triggering mucosal immunity imbalance; International Consensus on Anaemia Management in Surgical Patients (ICCAMS); Sleep disturbance trends in the short-term postoperative period for patients undergoing total joint replacement; Achilles tendon tissue turnover before and immediately after an acute rupture; Quadriceps or hip exercises for patellofemoral pain? A randomized controlled equivalence trial; Total-body MRI for screening in patients with multiple osteochondromas

Quadriceps tendon ruptures are a rare but debilitating injury resulting in loss of knee extension necessitating surgical intervention. Currently, multiple different surgical techniques and rehabilitation programs are utilized by surgeons. Researchers have been unable to determine the best surgical technique with respect to function and complication rate; certain techniques are more cost-effective than others. Early vs. late motion rehabilitation programs are utilized; recent evidence suggests that less aggressive initial rehabilitation may lead to decreased extensor lag and fewer additional surgeries. The goal of our study is to determine the treatment practices of orthopaedic surgeons across Canada. Our study was completed anonymously via . SurveyMonkey.com. (Palo Alto, California). Based on current literature, a 26-question survey was distributed. E-mail invitations were be sent to all members of the Canadian Orthopaedic Association. Participation is voluntary. Currently, 104 surveys have been completed. 78% of respondents utilize transosseous drill holes, 13% utilize suture anchors and 9% utilize a combined surgical technique. The majority of surgeons begin range of motion (ROM) at 2 weeks (42%) or 6 weeks (24%); ROM is then commonly progressed in a step-wise fashion at 2-week intervals (58%). Approximately half of respondents have performed revision surgery for quadriceps re-rupture. Surgical management of quadriceps tendon ruptures is fairly consistent amongst Canadian orthopaedic surgeons. However, wide variation exists regarding rehabilitation, favoring early initiation and progression of ROM despite some evidence recommending a longer period of immobilization

Introduction. Quadriceps performance following total knee arthroplasty (TKA) is a critical factor in patient satisfaction that can be significantly affected by implant design (Greene, 2008). The objective of this study was to compare quadriceps efficiency (QE) following TKA with a medial-pivot system (EVOLUTION®, MicroPort Orthopedics Inc., Arlington, TN, USA) to non-implanted control measurements. Methods. Five cadaveric leg specimens with no prior surgeries, deformities, or disease were obtained. Each was placed in a custom closed chain device and loaded to simulate a heel-up squat from full-extension to deep flexion (approximately 115°) and back to full extension. Quadriceps force (FQ) and ground reaction force (FZ) were measured, and the ratio of the two was calculated as the quadriceps load factor (QLF). QFLs are inversely related to QE, with higher QFLs representing reduced efficiency. Each specimen was then implanted with a medial-pivot implant by a board certified orthopedic surgeon and force measurements were repeated. Mean pre- (represents control values) and post-implantation QFLs were compared to determine any differences in QE throughout the range of motion. Results. Mean QFLs were not statistically different for pre- and post-implantation measurements throughout loading (Figure 1). QE was increased in the post-implantation measurements compared to pre-implantation between approximately 80° and 115° flexion and reduced between 5° and 80°. The mean peak post-implantation QFL was 5% less than that measured pre-implantation. Discussion. Quadriceps muscles were least efficient during peak flexion (80°–115°) when FQ was highest during both pre- and post-implantation measurements. The similar QE seen between the pre- and post-implantation measurements for most of the range of motion could be a result of the system design, which seeks to mimic the kinematics of the normal knee (Schmidt, 2003). The observed nearly-linear change in the FQ through 75° is likely due to the combination of the medial spherical radius and the conformity of the medial tibial insert socket that provides a constant moment arm on which the extensor mechanism can act. The primary driver of decreasing efficiency of the extensor mechanism is the increasing moment arm of the load with increasing flexion. The second increase in FQ in deep flexion (>110°) for the implanted measurements is likely due to the smaller closing radius on the femoral component in this range. These preliminary data have the potential to be significant clinically in that decreased QE may result in increased quadriceps forces manifesting in anterior knee pain or patient fatigue. Additionally, increased QE may play a role in rehabilitation and return to activities of daily living. The current results show the medial-pivot system may increase QE during peak flexion and does not significantly reduce QE during midflexion when compared to control. In-vivo testing is needed to confirm if these results translate to clinical practice

Most previous studies investigating autograft options (quadriceps, hamstring, bone-patella-tendon-bone) in primary anterior cruciate ligament (ACL) reconstruction are confounded by concomitant knee injuries. This study aims to investigate the differences in patient reported outcome measures and revision rates for quadriceps tendon in comparison with hamstring tendon and bone-patella-tendon-bone autografts. We use a cohort of patients who have had primary ACL reconstruction without concomitant knee injuries. All patients from the New Zealand ACL Registry who underwent a primary arthroscopic ACL reconstruction with minimum 2 year follow-up were considered for the study. Patients who had associated ipsilateral knee injuries, previous knee surgery, or open procedures were excluded. The primary outcome was Knee Injury and Osteoarthritis Outcome Score (KOOS) and MARX scores at 2 years post-surgery. Secondary outcomes were all-cause revision and time to revision with a total follow-up period of 8 years (time since inception of the registry). 2581 patients were included in the study; 1917 hamstring tendon, 557 bone-patella-tendon-bone, and 107 quadriceps tendon. At 2 years, no significant difference in MARX scores were found between the three groups (2y mean score; 7.36 hamstring, 7.85 bone-patella-tendon-bone, 8.05 quadriceps, P = 0.195). Further, no significant difference in KOOS scores were found between the three groups; with the exception of hamstring performing better than bone-patella-tendon-bone in the KOOS sports and recreation sub-score (2y mean score; 79.2 hamstring, 73.9 bone-patella-tendon-bone, P < 0.001). Similar revision rates were reported between all autograft groups (mean revision rate per 100 component years; 1.05 hamstring, 0.80 bone-patella-tendon-bone, 1.68 quadriceps, P = 0.083). Autograft revision rates were independent of age and gender variables. Quadriceps tendon is a comparable autograft choice to the status quo for primary ACL reconstruction without concomitant knee injury. Further research is required to quantify the long-term outcomes for quadriceps tendon use

Quadriceps moment arm is one of the factors determining quadriceps force. Total knee arthroplasty designs with larger quadriceps moment arms should generate less quadriceps and patellofemoral forces. A study was conducted to measure knee kinematics, quadriceps and patellofemoral forces in two knee designs with differing centers of rotation. In addition, the effect of a central dome-shaped versus a medialized patella component was determined. Six human cadaver knees were tested before implantation and after sequential implantation with two posterior cruciate retaining designs: Scorpio and Control. The quadriceps moment arm of the Scorpio design was 1 cm longer than that of the Control design. Knee kinematics was measured with an eletromagnetic tracking device while the knee was put through dynamic simulated stair climbing under peak flexion moments of 40 N-m. Quadriceps tension and patellofemoral compressive and shear forces were measured for both conditions and for the central and medialized patella components. The normal unimplanted condition showed increasing rollback with flexion while both implanted conditions displayed relatively less rollback. Overall, quadriceps tension was highest in the unimplanted condition and lowest in the Scorpio condition. The Scorpio design showed a 10-20% reduction in quadriceps tension at angles greater than 40° when compared to the Control design. Patellofemoral forces were also significantly reduced in the Scorpio design when compared to Control. There were no differences noted between the central and medialized patella component. The Scorpio design, with its more posterior center of rotation, reduced quadriceps tension and patellofemoral forces. Reduced quadriceps forces may facilitate postoperative rehabilitation and activities such as stair climbing. Reduction in patellofemoral forces could reduce patellar complications such as anterior knee pain, component wear and loosening. These results are currently undergoing validation with a prospective clinical study

Bone-patellar tendon-bone autografts, hamstring autografts or allografts are widely used grafts for ACL revision surgeries. Also use of quadriceps autograft for both primary and revision ACL surgeries is in an increasing popularity due to its biomechanical superior properties and less donor site morbidity. However, although several fixation techniques and devices for quadriceps tendon graft fixation on femoral side have been reported, literature lacks about biomechanical studies comparing properties of these different fixation techniques and devices. We aimed to investigate whether there is a difference between the fixation techniques of quadriceps tendon graft by using different fixation techniques and devices on the femoral side in terms of stiffness and amount of slippage in the tunnel. Full-thickness central parts of quadriceps tendons from paired knees of twenty five calf knees were fixed through a 10mm x 25mm tunnel in twenty five paired sheep femurs. Quadriceps tendon patellar side with soft tissue ending fixed with four different fixation devices (adjustable suspensory system (group 1), absorbable interference screw (group 2), titanium interference screw (group 3) and adjustable suspensory system + absorbable interference screw (group 4)) and quadriceps tendon with a patellar bone plug fixed with a titanium interference screw (group 5) were tested in a servohydraulic materials testing machine. 10 samples were included in each group. After applying a preload of 10 N, a cyclic force was applied for 20 cycles from 10N to 110N at a 1 hertz frequency. Amount of slippage in the tunnel was calculated as the difference measured in millimeters between length at 10 N after 20 cycles and starting length at 10 N (Graph 1). To determine the stiffness, a single load-to-failure cycle was performed at a strain rate of 20 mm/min as the last step (Figure 1). Rupture of the graft was not seen in any of the samples. Median values of amount of slippage in the tunnel were 6,41mm, 5,99mm, 3,01mm, 4,83mm, and 3,94mm respectively. Median values of maximum load at failure were 464N, 160N, 350N, 350N and 389N respectively. Amount of slippage in the tunnel was highest in the group 1 and was lowest in the group 3 (p<0.001). Group 1 was found to be most resistant group against load-to-failure test and group 2 was the weakest (p<0.001). However inter-group analyses between group 3 and 5 revealed that, although group 3 had the least slippage in the tunnel, group 5 was better in terms of stiffness, but there was no statistically significant difference (p=0,124 and 0,119 respectively). There was a significant difference between group 2 and 3 in both amount of slippage in the tunnel and stiffness (p=0,001 and 0.028 respectively)(Table 1). Our study revealed that, although quadriceps graft with a bone plug fixed with metal interference screws is widely presumed to be a stable fixation technique, there was no significant difference in terms of stiffness when compared with quadriceps graft with soft tissue ending fixed with a metal interference screw. Although adjustable suspensory device group was the best in the terms of resistance against load-to-failure, it was the worst in terms of amount of slippage from the tunnel. Thus, if a suspensory device is to be used, it must be kept in mind that a strong 20 cycles of intra-operative tension force must be applied to prevent further slippage of the graft in the tunnel which can result in failure of reconstruction. For any figures or tables, please contact the authors directly

Introduction: The goals of TKR are restoration of the mechanical axis, joint line and Q –angle. Reproduction of the offset of the extensor mechanism during arthroplasty is less well understood. The lever arm of the extensor mechanism is primarily affected by femoral component position, patella tracking and overall patellar thickness. Changing this lever arm alters quadriceps muscle and patellofemoral joint reaction force. Some TKR designs purposefully aim to increase this offset in order to reduce PFJ contact pressures. Overstuffing the PFJ will however adversely affect outcome. The aims of this study were to measure and compare the pre and postoperative quadriceps lever arm and its effect on function in a consecutive series of patients undergoing TKR. Methods: Fifty consecutive patients who had an LCS TKR without patellar resurfacing by a single surgeon were reviewed. Patient demographics were recorded. We measured the pre and post-operative quadriceps lever arm using comparable lateral radiographs and digital imaging software. Functional outcome in these patients was determined using the American Knee Society Score pre and 6-months post-operatively. Patients were specifically questioned regarding the presence or absence of anterior knee pain. Results: Quadriceps lever arm was on average 6 mm greater post-operatively than pre-op but this difference was not significant [t-test]. The functional outcome in these patients was independent of any change in quadriceps lever arm. Conclusions Reproduction of normal biomechanics is essential in order to optimise outcome from TKR. Using the LCS system, there is a small but insignificant increase in the quadriceps moment arm. We have not found that this has any bearing on functional outcome in these patients

Objective: The objective of this study is to evaluate the role of quadriceps tightness in patients with patellar symptoms. Material and methods: We evaluated 64 patients (12 men and 52 women) diagnosed of patellar malalignment, chondromalacia, patellar pain, patellar subluxation... in 100 knees. We defined 2 groups according the presence or not of imaging disorders: Group A (48 knees) with normal x-ray and CT-scan; group B (52 knees) with malalignment in x-ray or CT-scan. In both groups we evaluated quadriceps tightness by placing the patient prone and passively bringing the heels toward buttock. Average distance between heels/buttock (HBD) was 9.1 cm. in both groups before treatment and none presented HBD = 0 cm. Treatment consisted in passive quadriceps stretches after warm-up. Results: After 11 rehabilitation sessions (range: 9–12), average HBD was 2.5 cm. in group A and 3.6 cm. in group B. HBD = 0 cm. was present in 32/48 knees in group A and 12/52 knees in group B. With a follow-up of 36–48 months, patients with HBD = 0 and values of HBD similar to values after treatment were present in both groups. After follow-up, pain was reported in 4/36 patients in group A and 20/28 in group B. Conclusions: Quadriceps tightness is always present in patients with patellar symptoms and it is a valuable and reproducible sign. Passive quadriceps stretches are highly effective in patients with normal imaging tests and can be useful before surgery in patients with patellar malalignment

Patients with advanced osteoarthritis tend to have limited range of motion; the purpose of this in vivo anatomical study is to identify the anatomical structures responsible for limited knee movement in patients with osteoarthritis. Forty-two quadriceps releases were performed in patients who had TKA. The releases were carried out utilising subvastus approach and just before proceeding with the knee replacement surgery. The ranges of motion were documented before and after the release using digital photography and lateral portable X-ray. No bony resection was done, and no ligament release was performed. Quadriceps excursion was also studied under fluoroscopy in six volunteers throughout the range of movement. The quadriceps release improved the range of motion in all patients; at least 135 degrees of flexion were obtained. The improvements were more dramatic in patients who had previous surgeries. The average of improvement in knee flexion after the release was 36 degrees. The presence of osteophytes or gross deformity did not influence the degree of improvement. The fluoroscopy study has shown that the average excursion of quadriceps muscle from 0 to 145 degrees is 7 cm. The excursion per degree varies throughout the range of motion; it is more per degree near full flexion and extension than around 90 degrees of flexion. The limited excursion of the quadriceps muscle is the main limiting factor to full knee flexion. Other pathological changes such as osteophytes, surface pathology, posterior capsule and the cruciate ligaments play very limited roles

Background:. Total knee replacement (TKR) is a frequent and effective surgery for knee osteoarthritis. Postoperative pain is under concern and can be relieved by different methods, including femoral nerve block (FNB). The efficacy of FNB on pain relief was associated with the absence of clinical impact when measured with the range of motion (ROM). Recent studies suggest that the quadriceps strength is the best indicator of functional recovery after TKR. The goal of this study is to compare the quadriceps strength recovery after TKR according to the kind of analgesia (patient control analgesia (PCA) with or without FNB) Hypothesis: the FNB delays the QSR at short and mid-term follow-up. Methods:. Prospective randomized trial with single-blind assessment involving 135 patients admitted for TKR in an academic center. Randomization into one of the three following groups: A) Continuous FNB 48h + PCA B) Single-shot FNB and PCA C) PCA alone. Groups were comparable for demographic and surgical data. The FNB was realised and controlled (electric stimulation) by an expert anesthesiologist before the surgery. Follow-up standardised in all groups with blinded assessors. Quadriceps strength measured with a validated dynamometer at 6 weeks, 6 and 12 months. Secondary outcomes included clinical evaluation (ROM, pain, stability) and functional scores (SF-36 v2, WOMAC). Multivariate analysis (Kruskal-Wallis, Mann-Whitney) for main outcomes and Spearman factor for correlation. Sample size calculated for alpha 5% and study power 80%. Results:. 111 patients available for 6 weeks follow-up (A-B-C:40-38-33) and 104 (36-36-32) at 6 and 12 months. Two patients in group B excluded for direct fall in the first postoperative week with extensor mechanism rupture and peri-prosthetic femoral fracture. QSR is significantly decreased in patients with FNB at all times (mean, 95% IC): 6 weeks (A 51.3%, 44.1–58.5; B 62.2%, 55.2–69.2; C 77.4%, 70.7–84.1; p < 0,05), 6 months (A 65.4%, 57.9–72.9; B 82.1%, 74.2–90; C 95.7%, 88.5–102.9; p < 0,05) and 12 months (A 87.8%, 82.1–93.5; B 97.8%, 89–106.6; C 104.8%, 96.1–113.5; p < 0,05). No significant difference between continuous or single-shot FNB. Higher ROM in group C at all times (p 6 weeks = 0,046; p 6 months = 0,159; p 12 months = 0,026). No correlation between ROM and QSR (rho = 0,07; p = 0,23). Better functional results in the group C at all times (p < 0,05), with good correlation to QSR (rho = 0,177; p = 0,032). Slight difference in analgesic effect of FNB (p = 0,14). Conclusion:. Femoral nerve block has a negative influence on QSR at short and mid-term follow-up and delays the rehabilitation after TKR. QSR is actually the most sensitive indicator of functional recovery after TKR and is better related to functional tests than ROM. This can explain the harmlessness of FNB in previous studies. FNB should not yet be recommended for analgesia after TKR

Quadriceps femoris muscle (QFM) weakness is associated with the development of knee osteoarthritis (OA). Neuromusclar electrical stimulation (NMES) circumvents neural inhibition causing muscle contraction, however there is little reported data demonstrating its role in knee OA. Our aim was to evaluate the effectiveness of a NMES program in patients with knee OA. Sixteen patients (10 women, 6 men) with severe knee OA were randomised into control (n=6) or intervention (n=10) groups. These were similar in terms of age (64.8 ± 11.0 vs. 64.6 ± 7.6; mean ± SD) and BMI (31.8 ± 6.11 vs.30.7 ± 2.9). NMES was applied using a garment-based stimulator for 20 min/day, 5 d/wk for 8 weeks. Isokinetic and isometric QFM strength were determined at baseline, and weeks 2, 5, and 8 using a dynomometer. Functional assessments involved a 25 metre timed walk test (TWT), timed stair-climb test (SCT), and timed chair-rise test (CRT) at baseline and week 8. Subjects recorded NMES session duration in a log book while the device also recorded total treatment time. Function significantly improved in the NMES group as determined by the timed SCT (p< 0.01) and the timed CRT (p< 0.01) at week 8 compared to week 0. Isometric QFM strength was significantly higher in the NMES group at weeks 2, 5 and 8 than week 0. Compared to week 0, isokinetic hamstring strength increased significantly in the NMES group at week 2, week 5 and week 8 while isokinetic QFM strength increased at week 5 (p< 0.05) and week 8 (p< 0.01). Patient recorded compliance was 99.5% (range, 97.1%–100%) and overall usage recorded on the stimulator was 96.1% ± 13.2. The use of a portable home-based NMES program produced significant QFM strength gain with associated improvement in function in patients with severe knee OA. Compliance was excellent overall

Intro: Quadriceps rupture following total knee arthroplasty is a devastating injury. Early operative repair is necessary to maintain the integrity of the extensor. Postoperative rehabilitation usually involves a prolonged period of immobilisation to allow the repair to consolidate. This immobilisation can cause irreversible stiffness in the patient with a total knee replacement. We present a method of rehabilitation to allow early range of motion. Case Report: A 57 year old gentleman presented with bilateral tri-compartmental osteoarthritis, he had no other significant medical history. Bilateral synchronous total knee replacements were performed and the early post operative was unremarkable. The patient fell whilst mobilising indoors at home during the fifth post operative week and sustained rapid hyperflexion injures to both knees. Ultrasound scans of the knees demonstrated bilateral discontinuities of the quadriceps mechanisms and a large fluid collection filling the defect. The patient returned to the operating where a direct repair was achieved. Post operatively the patient was rested in bilateral cylinder casts until the sutures were removed at two weeks. For two week periods the knees were then mobilised in a hinged cast brace allowing 0–30, 0–60 and 0–90 degrees making the total time in cast 8 weeks. At the time of removal of the casts the patient had 110 degrees of flexion in the right leg and 85 degrees of flexion in the left. At six months postoperatively the patient flexes freely to over 100 degrees. Conclusion: Bilateral quadriceps ruptures in a relatively young patient can be managed with early repair and an aggressive rehabilitation regime. This case suggests that is possible to achieve a satisfactory outcome although the input required is significant

Introduction & aims: Quadriceps muscle wasting is common in patients with osteoarthritis (OA) of the hip and knee. Previous studies,using ultrasound and performing biopsies, have demonstrated quadriceps muscle fibre atrophy. Thigh girth measurements are quoted in textbooks as a means of quantitatively assessing muscle bulk. This study has looked at these measurements in patients with hip and knee OA to see if these measurements are useful. Method: 87 patients (mean age 62, range 36–87) with a diagnosis of OA were seen in the pre-assessment clinic. 47 were awaiting total hip replacement (THR) and 40 were awaiting total knee replacement (TKR).All were awaiting primary arthroplasty and had not had previous joint surgery. Thigh girth measurements were taken at 2 points corresponding with one-third and two-thirds of the length between the anterior superior iliac spine and the tibial tuberosity. These measurements were taken for both thighs. The observed differences were analysed with normal probability plots and paired Student’s t-tests. Results: No significant difference in thigh girth could be detected in patients awaiting total knee replacement. Girth was significantly reduced in the thigh on the side of planned THR. This difference was apparent when measured both proximally and distally. Conclusion: Measurements of thigh girth were not useful indicators of quadriceps wasting in patients awaiting TKR. Patients awaiting THR should have thigh girth measured, those with reduced thigh girth on the side of planned arthroplasty may have quadriceps atrophy and can then be referred for physiotherapy prior to surgery

Introduction

Anterior cruciate ligament (ACL) injuries represent a significant burden of disease to the orthopaedic surgeon and often necessitate surgical reconstruction in the presence of instability. The hamstring graft has traditionally been used to reconstruct the ACL but the quadriceps tendon (QT) graft has gained popularity due to its relatively low donor site morbidity.

Background: Quadriceps femoris muscle (QFM) weakness has been implicated in the development of knee osteoarthritis (OA) as well as predicting functional ability after TKA. Preoperative strengthening (prehabilitation) may be facilitated by applying neuromuscular electrical stimulation (NMES) to the affected QFM using a garment-based portable stimulator. Methods: Single blind, randomised control efficacy study with NMES applied to the affected QFM for 20 min, 5 days a week, for 8 weeks pre-TKA. Isokinetic and isometric strength was assessed at baseline, week 2, week 5 and immediately pre-op. Function was assessed using a 25 metre timed walk test (TWT), timed stair-climb test (SCT), and timed chair-rise test (CRT) at baseline and pre-op. Results: 13 patients (8 women and 5 men) scheduled for TKA for knee OA were recruited and randomised into a control (n=5) or intervention (n=8) group. Groups were similar in terms of age (65.5 ± 6.8 vs. 61.8 ± 9.0; mean ± SD) and BMI (29.7 ± 2.1 vs.33.2 ± 5.6). There was an improvement in SCT (p< 0.01) and CRT (p< 0.01) in the NMES group at week 8 compared to week 0. Isokinetic hamstring strength and isometric QFM strength increased significantly at weeks 2, 5 and 8 compared to baseline whereas isokinetic QFM strength only increased at week 5 (p< 0.05) and week 8 (p< 0.01) compared to baseline. Conclusion: The use of a portable home-based NMES program for 8 weeks results in significant strength gains with associated improvements in function in patients scheduled for TKA for knee OA

Introduction

Patellofemoral instability is one of the most common presentations to a children's orthopaedic clinic. Recurrent patellar dislocations and instability episodes are painful, disabling and increase the risk of irreversible chondral damage. The medial patellofemoral ligament is the primary static stabiliser to prevent lateral dislocation of the patella and is almost always torn or attenuated in these cases. Reconstruction of this ligament is commonly performed using autologous hamstring tendon however there has been some interest recently in use of quadriceps tendon as a graft. Children with patellar instability also present unique challenges due to the small size of the patella and the presence of open growth plates which may require adaptations to the common techniques.

The aim of this study was to compare the results in patients having a quadriceps sparing total knee replacement (TKR) with those undergoing a standard TKR at a minimum follow-up of two years.

All patients who had a TKR with a high-flex posterior-stabilised prosthesis prior to December 2002 were reviewed retrospectively. There were 57 patients available for follow-up. Those with a quadriceps sparing TKR had less pain peri-operatively with a greater degree of flexion at all the post-operative visits and at the final follow-up, but their operations took longer, with less accurate radiological alignment. There was no difference in the complications and in the Knee Society scores between the two groups at the final follow-up.

Total knee replacement through a quadriceps sparing approach has some peri-operative advantages over the standard incision. At a minimum follow-up of two years the clinical results were similar to those with a standard incision, but the radiological outcomes of the quadriceps sparing group were inferior.

Abstract

Introduction

Chronic ruptures of the quadriceps tendon after total knee arthroplasty (TKA) are rare but are a devastating complication. The objective of this study was to validate the use of fresh frozen total fresh quadriceps tendon allografts for quadriceps tendon reconstruction. The hypothesis of this work was that the graft was functional in more than 67% of cases, a higher percentage than the results of conventional treatments.

Abstract

Abstract

Abstract

1. Previous reports of the role of the quadriceps in producing limitation of movement or dislocation of the patella have tended to implicate one particular part of the complex. Experience gained in thirty-five quadricepsplasties in children has shown that all parts of the quadriceps (except vastus medialis) and the ilio-tibial band also may play a part and that each of these must be attended to if a satisfactory result is to be obtained.

2. A simple technique of operation is described and illustrated.

3. Since this paper was prepared, a patient showing features of particular interest has been seen and treated.

1. Contracture of parts of the quadriceps muscle is not uncommon and is often accompanied by tightness of the ilio-tibial tract. It is suggested that this may follow intramuscular injections.

2. Recurrent dislocation of the patella can be a consequence of this muscle contracture.

3. Division of the ilio-tibial tract and lengthening of the fibrotic elements of the quadriceps can prevent further dislocation and restore good function.

To explain the knee kinematics, the vector of the quadriceps muscle, the primary extensor, is important and the relationship of the quadriceps vector (QV) to other kinematic and anatomic axes will help in understanding the knee.

Knee kinematics is important for understanding knee diseases and is critical for positioning total knee arthroplasty components. The relationship of the quadriceps to knee has not been fully elucidated. Three-dimensional imaging now makes it possible to construct a computer based solid model of the quadriceps and to calculate the vector of the muscle as individual parts and as a whole. Two studies are presented, one American and one Japanese subjects.

Using CT data from subjects who had CT for reasons other than lower extremity pathology (American) or specifically for the study (Japanese), 3-D models of each quadriceps component (vastus medialis, intermedius, lateralis and rectus femoris) were generated. Using principal component analysis for direction and volume for length, a vector for each muscle was constructed and addition of the vectors gave the QV. Three anatomic axes were defined: Anatomic Axis (AA) – long axis of the shaft of the femur; Mechanical Axis (MA) center of the femoral head to the center of the trochlear and the Spherical Axis (SA) – a line from the geometric center of the head of the femur to the geometric center of the medial condyle of the femur at the knee.

Fourteen American cases (mean age 39.1, 9 male 5 female) and 40 Japanese subjects (mean age 29.1, 21 male, 19 female) were evaluated. In all subjects the quadriceps vector at the level of the center of the femoral head was anterolateral to the center of the femoral head. The position of the QV was more lateral in Japanese compared to Americans; and, in Japanese, the vector was more lateral and posterior for women than for men. In both study populations, the QV was most closely aligned with the SA as compared to the AA or the MA.

The vector representing the quadriceps pull, originating at the top of the patella, progresses proximally toward the neck (not the head) of the femur. With the femur in anatomic position in the coronal plane, the vector crosses the femoral neck lateral to the femoral head approximately at the midpoint of the neck. While there were significant differences between the passing point of the vector based on sex and ethnicity, the QV vector most closely parallels the SA (< 1° different) for all subjects in this study. The relationship of the SA to the kinematic flexion axis (KFS) of the knee is being evaluated with the hypothesis that the relationship is 90°. If this is correct, the SA may prove a robust axis to which to align total knee arthroplasty.

We conclude that the QV as calculated progresses from the top of the patella to the mid-femoral neck and the SA is most closely parallel to this vector.

Our study is still in progress. The results mentioned in the abstract are preliminary results. The final results will be provided at the time of presentation.

Over the past decade, the widespread availability of high-resolution ultrasonography coupled with advances in regional anaesthesia have popularised peripheral nerve blocks for anterior cruciate ligament reconstructions (ACLRs). The aim of this study is to investigate whether the femoral nerve block (FNB) administered at the time of ACLR has any long-term impact on the quadriceps strength as compared to patients who did not receive a FNB.

This is a retrospective study. Four hundred charts of patients who underwent ACLR at our institution and had subsequent Biodex testing (an isokinetic rehabilitation test that provides objective information about muscle strength deficits and imbalances of the operated leg compared to the non-operated leg) from 2004 to 2015 were reviewed. Patients who had prior ipsilateral knee surgery, multi-ligament knee injury or at extreme ages were excluded from the study. The following baseline patient characteristics was recorded for each reviewed chart: age, sex, medical comorbidities, the date of the injury, date of the surgery, surgery technical notes and associated procedures, the surgeon, the hospital were the patient was operated, the Biodex test date and the Biodex test results. Data extraction assessed any association between the ACLR patients' who received FNB with the results of the Biodex test after completing the rehabilitation protocol. Descriptive statistics were used to compare the type of anaesthesia, mode of pain control and the results of the Biodex tests between patients grouped by the mode of anaesthesia used at the time of surgery (FNB versus no FNB). A multivariate regression model then compared quadriceps strength (inferred by Biodex test results) between groups while controlling for baseline differences between groups.

Fifty five percent of the ACLR patients received FNB compared to 45% that did not receive FNB over the last 11 years of performing ACLRs (2004–2015) at our institute. Fifty percent of the patients that received FNB failed to achieve more than or equal to 80% quadriceps strength (compared to the contralateral non-operated leg) at 6 months on Biodex test. On the other hand, only 20% of the non-FNB group failed to achieve more than or equal to 80% quadriceps strength.

This study lead us to think that ACLR patients that received FNB are significantly weaker in quadriceps strength at 6 months post ACLR in comparison to non-FNB ACLR patients. This finding subsequently might affect the time needed to return to sports and might indicate a considerable clinical consequence of the FNB on ACL-reconstruction patients.

The acetabular labrum serves many integral functions within the hip joint. As a result, novel surgical techniques that aim to preserve or reconstruct the labrum have entered the spotlight. We have successfully performed a labral reconstruction using the quadriceps tendon as an autograft for a patient with a moderate labral defect. The purpose of this report is to propose this novel donor site as a viable alternative for labral reconstruction using an autograft; the potential benefits over currently popular methods will be discussed.

The current indications for functional restoration of extension of the knee following quadriceps resection or loss require reappraisal. The contribution of pedicled and free functional muscle transfer is likely to be over-emphasised in many studies, with good functional outcomes predominantly reported only in the context of cases with residual quadriceps function. In cases with total quadriceps resection or loss, all forms of reconstruction perform poorly. Furthermore, in smaller resections with loss of two or fewer components of the quadriceps, minimal impairment of function occurs in the absence of functional reconstruction, suggesting that functional restoration may not be warranted. Thus there is a paradox in the current approach to quadriceps reconstruction, in that small resections are likely to be over-treated and large resections remain under-treated.

This review suggests a shift is required in the approach and rationale for reconstructing functional extension of the knee after quadriceps resection or loss. A classification based on current evidence is suggested that emphasises more clearly the indications and rationale for functional transfers.

Recent emphasis in total knee arthroplasty has been on accelerated rehabilitation and recovery. Minimally invasive and quadriceps sparing techniques have been developed to expediate return to normal function. The aim of this study was to evaluate the effect of the tourniquet on post-operative pain and quadriceps function in total knee arthroplasty.

This study involved a randomised, blinded, prospective trial of 20 patients undergoing total knee arthroplasty by a single surgeon. All patients received a general anaesthetic, identical prosthesis and post-operative protocol. Patients were randomly allocated to one of two group: (a) tourniquet group or (b) no tourniquet group. A standard surgical tourniquet was applied to all patients but only inflated in the tourniquet group.

Outcomes included Oxford knee scores, post-operative pain scores, post-operative drainage and transfusion requirements, thigh and knee circumference measurements, range of motion, and surface EMG measurements at intervals of two weeks, six weeks, six months and twelve months.

The study included 16 male and four female patients with 11 right and nine left knees. There was no significant difference pre-operatively between groups in age, degree of deformity or range of motion.

There was no significant difference detected between Oxford knee scores up to twelve months, days to discharge, post-operative drainage and range of motion. However, the pain scores were significantly higher in the tourniquet group. Surface EMG as a measurement of quadriceps activation showed a significant difference between the groups and between time points. The no tourniquet group can support more energy in their quads muscle than the tourniquet group

The use of a tourniquet in total knee arthroplasty has no effect on overall knee function at twelve months as measured by the Oxford knee score and range of motion; however tourniquet use results in higher initial pain scores and reduction in quadriceps function as measured by surface EMG.

Purpose: A relationship between vastus medialis oblique (VMO) strength and anterior pain and disability has been suggested. A biomechanical protocol was used to access the deficiency of the quadriceps muscles in patients with anterior knee pain.

Methods and Results: A biomechanical evaluation was conducted on 54 patients with anterior knee pain (34 females and 20 males). All patient x-rays were normal through interpretation by a blinded radiologist. A Kistler force plate, a VICON motion analysis system and surface electromyography were used to quantify biomechanical function during isometric, walking and squatting exercises.

For 42 of the 54 (78%) subjects, during isometric and walking exercises we observed that activation of the VMO, rectus femoris (RF) and vastus lateralis (VL) muscles of the symptomatic leg was not significantly different from those of the asymptomatic leg (p< 0.01). However, for 31 patients (57%) during the eccentric phase of the squat exercises, the symptomatic leg presented with high activation of VL compared to VMO and RF (p< 0.01). During the concentric phase, 45 patients (83%) presented with higher activation of the VL compared to the VMO.

Conclusion: VMO activity during squatting for the symptomatic patient with anterior knee pain leg differs fundamentally during walking and isometric exercise compared to squatting tasks. Moreover, the relative contribution of the VL compared to the VMO during the eccentric phase of the squat exercises was different to those recorded during the concentric phase. Therefore, we suggest that maximal isometric and or isokinetic exercises are not sufficient to access the quadriceps function in relation to anterior knee pain. A thorough biomechanical assessment, including functional testing to reproduce the patient’s pain and locate the nature of the symptoms is suggested.

1. Six cases of quadriceps contracture in children are described. All were either premature or suffered severe illnesses soon after birth.

2. Some additional information is given about cases of the same condition previously published by other authors.

3. It is suggested that injections and infusions given to newborn babies are sometimes the cause of the condition.

4. Some of the therapeutic substances and measures which may be responsible are discussed. These include antibiotics, vitamin K preparations and "subcutaneous" fluid therapy.

Summary Statement

ACL reconstruction using a quadriceps tendon autograft was quantitatively evaluated using a robotic testing system. Biomechanical results on joint stability and graft function support its use as an alternative to the hamstrings.

Introduction In the past years a lot of interest has been raised on the mini-invasive surgical techniques in many fields of orthopaedic surgery.However,true innovative techniques have been rarely proposed,other then reducing the length of the incision with the aid of specially designed tools,particularly in the hip surgery.In the knee also, shorter scars should not be considered as the main purpose of the so called MIS(minimally invasive surgery)but as the side beneficial effect and the natural consequence of a more conservative technique,sparing soft tissues such as the quadriceps tendon,the extensor mechanism and the suprapatellar pouch,as well as nervous tissue and vascular supply.Considering this,the Mis-Quad Sparing technique is a really new technique,that has in view the object to preserve anatomic structures,and in particularly the extensor apparatus.

Patients and methods From june 2003 to june 2004 we’ve studied two homogeneous cohorts of patients uniform for age,gender,BMI and local and radiographic objectivity(Baseline characteristics have been compared between groups by means of Student T test or Fisher exact test)operated with the same implant(Zimmer, NexGen CR),one with QS technique(30 patients)and one with the standard approach(26 patients).

For the post-operative evaluation and for the critical comparison of the two groups we’ve considered the following parameters:length of operation,blood loss,ROM(at discharge,at 1 month,at 3 months,at 6 months),functional scores(using the Knee Society Assessment& Function Score),implants position and postoperative pain.In order to evaluate the differences among the two groups over time,we adopted a general linear model for repeated measures with calculation of Huber White robust standard errors to account for intra-patients correlation over time: a 2 sided p-value< 0.0125 was considered significant and Bonferroni correction was applied for post-hoc test.

Results and discussion The study has demonstrated that the Mis-QS technique allows less blood loss(p< 0.001 at all times considered),less pain (mean 10 points less with VAS),more rapid and better functional restoration (significant differences,p< 0.001,observed between groups and over time),with the same length of operation(at mean QS required only 10′ more than standard)and the same implant’s precision(p> 0.30 for all implant’s angles considered).Therefore,the supposed advantages of the QS technique can be considered real,based on our statistical comparison

Recurrent patellar dislocation is a relatively common disorder in young patients. Historically, treatment options have been based on the underlying disorder predisposing the patient to the dislocation. This has resulted in various soft tissue reefing procedures, patella tendon realignment procedures and boney realignment procedures.

Further research has shown that the medial patello-femoral ligament (MPFL) is the primary restraint to lateral patella subluxation and dislocation. Many authors have published their successful treatment of recurrent patella dislocation by reconstruction of the medial patellofemoral ligament. The most widely used is autologous semitendinosis tendon grafts, as well as synthetic materials, and MPFL reconstructions may be combined with boney procedures. Varieties of fixation techniques have been described involving both the patella and femoral sides.

We present a technique of MPFL reconstruction using the autologous ipsilateral quadriceps tendon. Our technique avoids the morbidity associated with semitendinosis graft harvesting and the drill holes in, and potential resulting fracture of, the patella. The technique is also simple and is associated with decreased procedure costs.

We present the technique and a series of six patients (seven knees) with follow up ranging from eight months to nine years. The average age of patients at the time of surgery 16 to 28 years (mean = 20 years). There have been no redislocations. The median Kujala patellofemoral knee score at follow up was 97 out of 100 (Range 69–100). The results compare very favorably to published results using other techniques.

Our technique of reconstructing the MPFL is reliable, produces good results using an objective knee score, and is cost effective.

Seventy staff members participated from a potential pool of approximately one hundred staff on duty at the time. Of the seventy staff who participated in this research project a total of three staff members were within 50 mls of the correct amount for each of the three samples. Overall staff were very poor at estimating blood loss.

Staff working in the operating theatre, no matter what their affiliation or years of experience, are not accurate when estimating blood loss spilt into a patients bed. A tool that aids in blood loss estimation is a valuable addition to the theatre resource manual.

Objective: Decreased quadriceps strength may contribute to anterior knee pain after total knee arthroplasty (TKA). The quadriceps force necessary to establish full extension is strongly dependent on the position and the relative length of the lever arms over the knee joint. The purpose of this in vitro study was to investigate the amount of quadriceps force required to extend the knee isokinetically after TKA in dependence of different prosthesis designs and the state of the posterior cruciate ligament (PCL).

Methods: Eight fresh frozen human knee specimens were tested in a kinematic device that simulated an isokinetic knee extension cycle from 120° of flexion to full extension. Knee motion was driven by a hydraulic cylinder applying sufficient force to the quadriceps tendon to produce an extension moment of 31 Nm. The quadriceps force was measured using a load cell attached to the quadriceps tendon after implantation of a cruciate retaining (CR) TKA (Genesis II, Smith& Nephew, Memphis, Tn, USA) applying a conventional and a highly conforming polyethylene (PE) inlay before and after resection of the PCL. Finally, the femoral component of the CR TKA was replaced by a posterior stabilized (PS) design and measurements were redone.

Results: No significant differences in the average quadriceps force were detected between the different PCL retaining inlays (CR, highly conforming) as long as the PCL was intact. However, after resection of the PCL, the required quadriceps force increased significantly for both designs (CR: 4.7%, p < 0.01, Highly conforming: 3.5%, p < 0.03). After implantation of the PS femoral component quad force decreased to its initial levels with forces significantly lower compared to the PCL deficient knees provided with a CR (−6.0%, p < 0.01) or highly conforming (−5.1%, p < 0.01) inlay. With a PS design average quadriceps extension force was not significantly different from cruciate retaining TKA inlays at an intact PCL.

Conclusions: The data of this in vitro study suggest that the quadriceps extension force is significantly higher for knees after cruciate retaining TKA with PCL deficiency, independent of the use of a CR or DD inlay. Thus, the integrity of the PCL should be secured in clinical practice when using a cruciate preserving TKA design.

Introduction: The technique of quadriceps sparing knee arthroplasty involves a pure capsular incision, without violation of the extensor mechanism. This capsular incision should be placed distal to Vastus Medialis Obliquus (VMO). The termination of VMO is variable and may make the quadriceps sparing approach difficult. We initiated this study based on the hypothesis that quadriceps sparing approach may not be possible in all the patients undergoing total knee arthroplasty. We examined MRI scans of the knee joint to assess the variation in VMO muscle insertion in relation to the patella and variation of VMO muscle insertion in relation to the age.

Material and Methods: Between Jan 2005 and Dec 2005, 262 MRI scans of the knee joint were performed at our institute. We studied MRI scans of the patients aged 16 years and over. The scans with neoplasm or those without complete set of films were excluded from the study. There were 198 scans available for analysis. Our cohort consisted of 106 female patients and 92 male patients with an average age of 43 years (range 16–86 years). One hundred and thirty four patients were aged less than 50 years and 64 patients were 50 years or older.

We measured patellar height, VMO length on the axial views of the scans. The VMO insertion was calculated from the data and we divided the patients into proximal and distal groups in relation to the VMO termination on the patella. The proximal group included patients with VMO termination proximal to the mid-point of the patella and distal group included patients with VMO termination at or distal to the mid-point of the patella.

Results: The median height of the patella in female patients was 32mm (range 24–44mm) and in male patients was 36mm (range 28–48mm). The VMO length from the apex of the patella was 13.5mm (range 4–28mm) in female patients and 16mm (range 8–32mm) in male patients. Overall there were 119 (60%) patients in the proximal group and 79 (40%) in the distal group. In 20% of patients aged more than 50 years, VMO terminated in the distal half of the patella. In patients less than 50 years old, 50% had the VMO termination in the distal half of patella. A statistically significant inverse relationship was noted between the level of insertion of VMO and the age of the patient (p-value > 0.001, Chi-square test). There was no statistically significant relation between the level of insertion of VMO and the sex of the patient, in either age group (p-value 0.339).

Conclusion: Younger patients are statistically more likely to have a VMO which terminated at or more distal to the mid-point of patella. Therefore, the quadriceps sparing approach may not be possible in these subjects, however it is possible in majority of older patients.

Introduction: The technique of quadriceps sparing knee arthroplasty involves a pure capsular incision, without violation of the extensor mechanism. This capsular incision should be placed distal to Vastus Medialis Obliquus (VMO). It is well known that the termination of VMO is variable and may make the quadriceps sparing approach difficult. We initiated this study based on the hypothesis that the quadriceps sparing approach is not possible in all patients undergoing total knee arthroplasty.

Methods: We examined the axial MRI images of the knee joint performed over a period of 12 months at our institute. A total of 198 MRI scans were analysed between two observers.

To calculate the patellar height the apex of the patella was considered as ‘Reference Slice 1’. The consecutive slices were followed distally to the last slice in which the patella was visible. From ‘Reference Slice 1’ VMO muscle was followed distally to the slice in which the muscle was last visible. We calculated the patella height and VMO muscle length as the product of the number of MRI slices and MRI slice thickness.

Results: Of the 134 patients aged less than 50 years, 68 patients (50.7%) had a VMO that terminated in the proximal half of the patella. Out of 64 patients aged 50 years or older, 51 patients (79.7%) had a VMO that terminated in the proximal half of the patella.

A statistically significant inverse relationship was noted between the level of insertion of VMO and the age of the patient.

Discussion: Our results will have an implication on the use of the quadriceps sparing approach, as they highlight another possible limitation of this approach. Patients need to be warned before the TKA that the quadriceps sparing approach may not be possible in all, especially if they are younger.

Background

Most of contemporary total knee systems address on improving of range of motion and bearing materials. Although new total knee designs in most systems accommodated the knee morphology according to gender differences, reestablishing of the same anterior offset of the distal femur during total knee arthroplasty (TKA) has not been well addressed. Furthermore, in most total knee systems, the anterior offset of the femoral component is constant regardless of the increment of the femoral size. We hypothesized that change of the anterior offset of the distal femur during TKA might affect the quadriceps strength and immediate clinical outcomes which may result in improved design of the future femoral component.

A prospective study was done to assess the outcome of MPFL reconstruction for patellar instability using quadriceps graft. MPFL reconstruction was done using superficial strip of quadriceps by an anteromedial incision and attached close to medial epicondyle of femur. There were 15 knees in thirteen patients with a mean age of 23.4 years. All patients had MPFL reconstruction and 5 had tibial tuberosity transfers. With a mean follow-up of 39.4 (12–57) months, the mean pre-op Kujala scores improved from 47.8 to 87.2. The mean Lysholm scores improved from 54.2 to 86.8. None of the patients had patella re-dislocations. MPFL reconstruction with quadriceps graft appears to be effective producing good results in patients with patellar instability.

1. A case of bilateral spontaneous and simultaneous rupture of the quadriceps tendons is described.

2. The underlying cause was found to be gouty affection of the tendons.

3. So far as is known, a similar case has not previously been recorded.

We hypothesize that tethering adhesions of the quadriceps muscle are the major pathological structures responsible for a limited range of motion in the stiff arthritic knee. Forty-two modified quadriceps muscle releases were performed on 24 patients with advanced osteoarthritis scheduled for total knee arthroplasty. The ranges of motion were documented intraoperatively both before and immediately after the release. Passive flexion improved significantly in all patients (mean, 32.4 degrees of improvement, P < .001) following a modified quadriceps release, despite any presence of osteophytes or severe deformities. These results strongly implicate adhesions of the quadriceps muscle to the underlying femur, which prevent the distal excursion of the quadriceps tendon, as the restrictive pathology preventing deep flexion in patients with osteoarthritis.

The purpose of this study was to evaluate any differences in quadriceps activation during functional activity between patients with patellofemoral problems and normal subjects.

24 patients and 11 controls were assessed. Surface EMG amplitudes were recorded from three parts of the quadriceps, vastus medialis obliquus (VMO), lower fibres of vastus lateralis (VLO) and rectus femoris (RF), whilst subjects stepped on and off a stool. These amplitudes were normalised to those from a maximal isometric voluntary contraction at 90° of knee flexion.

The patients activated their VMO significantly less effectively than controls (mean + SEM normalised peak amplitude was 1.06 + 0.09 in patients, compared to 1.41 + 0.12 in the control subjects). In the controls, most of the activity was seen with the knee in flexion, with very little activity with the knee in extension. In comparison, patients recorded less activity with the knee in flexion and more when the knee approached extension.

EMG amplitudes in isometric contractions at 60° of knee flexion were compared with those at 90°. VMO and VLO showed less activation at 60° in both groups of subjects, but in RF there was no difference in the EMG, between these two angles. This suggests that the motor control of VMO/VLO may be different from the bulk of the quadriceps.

We have shown that high activity in the VMO and VLO parts of the quadriceps appears to be important in an exercise that involved taking the body weight on one knee at around 90° of flexion. This high activity is likely to have two effects: it is important for the stability of the knee itself, and by increasing the area of contact, it reduces contact pressures. Patients with patellofemoral problems were unable to produce this needed activity in VMO. The VMO and VLO may have a different motor control from the bulk of the quadriceps, and in normal function, work synchronously. The loss of this synchronicity in patients with patellofemoral problems, could well help to explain the retropatellar pain that these patients experience.

Introduction

Patient demand for a less invasive surgical approach reducing the trauma induced to the joint has resulted in the development of Minimally Invasive Surgery (MIS). Although the length of the surgical incision is appealing to patients, the changes are not purely cosmetic. The surgery should not violate the extensor mechanism in any way. Incisions into the quadriceps tendon or into the vastus medialis muscle make the approach less difficult but this violation will slow the recovery and affect the ROM of the knee. In Asian knees, authors found the variation of VMO, which is essential in early functional recovery in TKA patient, is so much, so new clinical test for MIS QS should be needed to show location relationship between the upper pole of the patella and the insertion of VMO itself to avoid unnecessary injury of VMO during TKA.

Neglected rupture of quadriceps tendon is an infrequently occurring lesion resulting from sport, but it is very interesting as regards the physiological and functional repercussions. The lesion is common in football players. The pathogenesis is a flexion trauma of knee. Many authors point out the importance of a pre-existent degeneration due to exogenous and endogenous factors. Pain, inextensible knee, ecchymosis, axe hit are a common presentation in acute events, difficult knee extension and pain in chronic. X-ray study shows calcification at the tendon-bone junction.

The treatment of neglected rupture of quadriceps tendon is surgical. If a defect of 5 cm or more is present between the ends of tendon the fascia lata can be used to correct the gap. When the ends can be apposed an end-to-end repair is possible. We treated a neglected rupture of quadriceps femoris muscle tendon in a bodybuilder with a particular technique: we stripped and harvested the semitendinosus and gracilis tendon and sutured them together. Then we made a transverse hole in the mid-portion of the patella; the tendons were passed through the transverse hole in the patella and sutured with the lateral, medial and intermendial vastus, and with the rectum femoral. At 6-month follow-up the patient has no pain and stability is improved, a practical range of knee motion regained. Full forceful extension is not completely restored.

The subvastus approach to the knee has been described as early as 1929. This approach for primary total knee arthroplasty (TKA) maintains the integrity of the quadriceps mechanism and maintains the vascularity of the patella.

We have conducted a prospective, double blind, randomised trial to evaluate the quadriceps function in TKA after the paramedian and the subvatus approaches in 40 patients with osteoarthitis. Patients were randomised to the two groups and were evaluated by an independent observer blinded to the approach used. The two groups were compared as regards function (range of motion, quadriceps lag, quadriceps power); functional outcomes (Hospital for Special Surgery scores); patellofemoral alignment (Patellar tilt); and operative time, blood loss and hospital stay.

There was a statistically significance difference between the two groups as regards quadriceps power and lag in the first post-operative week. The subvastus group performed better than the paramedian group. The range of motion was also better in the subvastus group, though this difference was not statistically significant. The subvastus approach avoids the painful inhibitory arc of the quadriceps and allows for better and rapid rehabilitation in the early post-opertaive phase.

There were fewer lateral retinacular releases in the subvastus group. The presence of an intact extensor mechanism allows for more accurate assesment of the patellofemoral alignment intraoperatively. The patello-femoral alignment readings were better in the subvastus group. The subvastus approach does not interfere with the vascular supply of the patella.

The patients operated by the subvatus group were discarged from hospitals early.

Background

Continuous epidural anesthesia or femoral nerve block has decreased postoperative pain after total knee arthroplasty to some extent. Although the established efficacy of these pain relief method, some adverse events such as hematoma or muscle weakness are still problematic. Intraoperative local infiltration of analgesia (LIA) has accepted as a promising pain control method after total knee arthroplasty. The safety and efficacy of LIA has been reported, although there are still limited evidence about the effect of LIA on quadriceps function and recovery of range of motion in early post-operative phase. The purpose of this study is to compare the quadriceps function and range of motion after TKA between the LIA with continuous epidural anesthesia and continuous epidural anesthesia alone.

Long term quadriceps strength defictis have been reported after a TKA performed with a quadriceps splitting approach. Will an MIS-TKA performed with a mini midvastus approach significantly improve long term quadriceps strength retention?

147 subjects were chosen in a retrospective manner for this study. 52 MIS-TKA, 48 quadriceps splitting TKA, and 47 controls with normal knees and no prior surgery. All groups were age and gender matched. All knees were tested more than 1 year after the index operation on a Cybex isokinetic dynamometer. All surgeries were performed by the author.

The average Knee Society knee score for the MIS-TKA group was 94.3 and the average age was 71. The quadriceps splitting group had an average knee score of 95.7 and an average age of 72. The control group had an average age of 70. All groups averaged 38% male and 62% female. At 30 degrees from full extension the MIS-TKA group retained 96.6% of the control group strength and the quadriceps splitting group 94.5%. At 15 degrees from full extension the MIS-TKA group improved to 99.7% while the quadriceps splitting group fell to 85% of the control group strength.

MIS TKA with a mini midvastus approach preserves terminal quadriceps strength better than a standard quadriceps splitting approach.

The drive in contemporary medicine is improved utilisation of scarce resources and a faster turn around of patients, with patients seeking faster recovery from surgery. Delaying factors in discharge from hospital following total knee replacement surgery include the time taken to get active extension and a straight leg raise following surgery. A retrospective case matched study of 20 patients shows that reducing the length of incision into the quadriceps tendon, therefore sparing the quadriceps mechanism speeds the post operative recovery significantly. Reducing the average time to discharge from 9.6 days in the control group to 3.2 days in the quadriceps-sparing group. All but one patient had an ASA grade of 2 with no significant co-morbidity in either group. No patient in either group suffered a post-operative medical event precipitating a delayed discharge. The criteria for discharge were the same in both groups.

Introduction

Electromyography (EMG) is the best known method in obtaining in vivo muscle activation signals during dynamic activities, and this study focuses on comparing the EMG signals of the quadriceps muscles for different TKA designs and normal knees during maximum weight bearing flexion. It is hypothesized that the activation levels will be higher for the TKA groups than the normal group.