Biomechanical stimuli have fundamental roles in the maintenance and remodeling of ligaments including collagen gene expressions. Mechanical stretching signals are mainly transduced by cell adhesion molecules such as integrins. However, the relationships between stress-induced collagen expressions and integrin-mediated cellular behaviors are still unclear in anterior cruciate ligament cells. Human ACL cells were harvested from ligament samples donated by patients who underwent total knee arthroplasties with informed consents. Interface cells were isolated from the 5-mm-end of ACL. Midsubstance cells were cultured from the middle part of ACL. The cells were seeded onto stretch chambers (2Ä−2 cm, 50,000 cells/chamber) and uni-axial cyclic mechanical stretch (0.5 Hz, 7%) was applied for 2 h using a ST140. RNA samples were reverse-transcripted and quantitative real-time RT-PCR analysis were performed. To inhibit the function of integrin alphaVbeta3 subunit or alpha5 in stretching experiments, anti-human integrin alphaVbeta3 and alpha5 functional blocking antibodies (alphaVbeta3: 20 mg/ml, alpha5: 4 mg/ml) were used. To investigate the cellular attachments responding to mechanical stretch, we observed the distribution of integrins and stress fibers in both ACL cells. The shape of midsubstance cells showed spindle and fibroblastic cellular morphologies. On the other hand, the interface cells displayed chondroblastic appearances such as small and triangular morphologies. The expressions of COL1A1, COL2A1, and COL3A1 genes were detected in the tissue RNAs of interface zones. However, these expressions were decreased in cultured interface cells. In midsubstance cells, the expression of COL1A1 gene was equally detected in both tissues and cultured cells. COL3A1 gene expression was maintained in cultured midsubstance cells. These results indicated that the phenotypes of both ACL cells were changed by cultured conditions, especially in the interface cells. After mechanical stretch, the COL1A1 expression of midsubstance and interface cells were stimulated up to 6 and 14-fold levels of each non-stretched control, respectively. The COL3A1 expressions were also enhanced up to 1.8-fold level of controls by stretching treatment in both cells. Integrin alphaVbeta3 was shifted to the peripheral edge of cells by stretching treatment. In addition, mechanical stretch changed the integrin alphaVbeta3-dependent stress fiber formation in both ACL cells. The functional blocking of integrin alphaVbeta3 inhibited stretch-activated COL1A1 and COL3A1 expressions. However, the functional blocking of integrin alpha5 did not suppress the stretch-induced COL1A1 and COL3A1 expressions in both ACL cells. Cultured interface cells loose their phenotypes in collagen gene expressions. However, mechanical stretch reproduces the expression of COL1A1 and COL3A1 genes in cultured ACL cells. The present study demonstrated that stretch-activated collagen gene expressions depend on the integrin alphaVbeta3-mediated cellular adhesions

Introduction. Sheffield Children's Hospital specialises in limb lengthening for children. Soft tissue contracture and loss of range of motion at the knee and ankle are common complications. This review aims to look at therapeutic techniques used by the therapy team to manage these issues. Materials & Methods. A retrospective case review of therapy notes was performed of femoral and tibial lengthening's over the last 3 years. Included were children having long bone lengthening with an iIntramedullary nail, circular frame or mono-lateral rail. Patients excluded were any external fixators crossing the knee/ankle joints. Results. 20 tibial and 25 femoral lengthening's met the inclusion criteria. Pathologies included, complex fractures, limb deficiency, post septic necrosis and other congenital conditions leading to growth disturbance. All patients had issues with loss of motion at some point during the lengthening process. The knee and foot/ankle were equally affected. Numerous risk factors were identified across the cohort. Treatment provided included splinting, serial casting, bolt on shoes, exercise therapy, electrical muscle stimulation and passive stretching. Conclusions. Loss of motion in lower limb joints was common. Patients at higher risk were those with abnormal anatomy, larger target lengthening's, poor compliance or lack of access to local services. Therapy played a significant role in managing joint motion during treatment. However, limitations were noted. No one treatment option gave preferential outcomes, selection of treatment needed to be patient specific. Future research should look at guidelines to aid timely input and avoid secondary complications

Introduction. Compartment syndrome can be a life changing consequence of injury to a limb. If not diagnosed and treated early it can lead to permanent disability. Neurovascular observations done on the ward by nursing staff, are often our early warning system to those developing compartment syndrome. But are these adequate for detecting the early signs of compartment syndrome? Our aim was to compare the quality and variability of charts across the UK major trauma network. Materials & Methods. All major trauma centres in England and Scotland were invited to supply a copy of the neurovascular chart routinely used. We assessed how such charts record relevant information. Specific primary data points included were pain scores, analgesia requirements, pain on passive stretch and decreased sensation in the first web space specifically. As secondary objectives, we assessed how late signs were recorded, whether clear instructions were included, quantitative scores and the use of regional blocks recorded. Results. A response rate of 46% was achieved. Of the charts reviewed, 25% documented pain scores or pain on passive movement. Pain on movement and analgesia requirements were documented in 33% and 8% respectively. Specific sensation within the 1. st. webspace was recorded in 16%. No charts recorded use of regional block. All charts recorded global sensation, movement (unspecified), pulse and colour whilst 66% documented capillary refill and 83% temperature. Instructions were included in 41% of charts. Conclusions. In 2016, the BOA supported publication of an observation chart for this purpose however, it is not widely used. In our study, late signs of compartment syndrome were generally well recorded. However, documentation of early signs and regional blocks was poor. This may lead to delays in diagnosis with significant clinical and medicolegal consequences. Standardisation of documentation by updating and promoting the use of the pre-existing chart would ensure highest quality care across the network

The etiology of the flexion contracture is related to recurrent effusions present in a knee with end-stage degenerative joint disease secondary to the associated inflammatory process. These recurrent effusions cause increased pressure in the knee causing pain and discomfort. Patients will always seek a position of comfort, which is slight flexion. Flexion decreases the painful stimulus by reducing pressure in the knee and relaxing the posterior capsule. Unfortunately, this self-perpetuating process leads to a greater degree of contracture as the disease progresses. Furthermore, patients rarely maintain the knee in full extension. Even during the gait cycle the knee is slightly flexed. As their disease progresses, patients limit their ambulation and are more frequently in a seated position. Patients often report sleeping with a pillow under their knee or in the fetal position. All of these activities increase flexion contracture deformity. Patients with excessive deformity >40 degrees should be counseled regarding procedural complexity and that increasing constraint may be required. Patients are seen preoperatively by a physical therapist and given a pre-arthroplasty conditioning program. Patients with excessive flexion contracture are specifically instructed on stretching techniques, as well as quadriceps rehabilitation exercises. The focus in the postoperative physiotherapy rehabilitation program continues toward the goal of full extension. Patients are instructed in appropriate stretching regimes. Patients are immobilised for the first 24 hours in full extension with plaster splints, such as with a modified Robert Jones dressing. This dressing is removed on postoperative day one. The patient is then placed in a knee immobiliser and instructed to wear it at bed rest, during ambulation and in the evening, only removing for ROM exercises. In cases of severe flexion deformity >30 degrees, patients are maintained in full extension for 3–4 weeks until ROM is begun. Patients are encouraged to use a knee immobiliser for at least the first 6 weeks postoperatively. Treating patients with flexion contracture involves a combination of bone resection and soft tissue balance. One must make every effort to preserve both the femoral and tibial joint line. In flexion contracture the common error is to begin by resecting additional distal femur, which may result in joint line elevation and mid-flexion instability. The distal femoral resection should remove that amount of bone being replaced with metal. Attention should be directed at careful and meticulous balance of the soft tissues and release of the contracted posterior capsule with re-establishment of the posterior recess, which will correct the majority of flexion contractures. Inability to achieve ROM after TKA represents a frustrating complication for both patient and surgeon. Non-operative treatments for the stiff TKA include shoe lift in contralateral limb, stationery bicycle with elevated seat position, extension bracing, topical application of hand-held instruments to areas of soft tissue-dysfunction by a trained physical therapist over several outpatient sessions, and use of a low load stretch device. Manipulation under anesthesia is indicated in patients after TKA having less than 90 degrees ROM after 6 weeks, with no progression or regression in ROM. Other operative treatments range from a downsizing exchange of the polyethylene bearing to revision with a constrained device and low-dose irradiation in cases of severe arthrofibrosis

Introduction. Early hip OA may be attributed to smaller coverage of the femoral head leading to higher loads per unit area. We hypothesize that tight hamstrings may contribute to increased loads per unit area on the femoral head during gait. When a patient has tight hamstrings they cannot flex their pelvis in a normal fashion which may result in smaller coverage of the femoral head (Figure 1). This study aimed to determine if subjects with tight hamstrings can improve femoral head coverage during gait after a stretching intervention. Methods. Nine healthy subjects with tight hamstrings (popliteal angle>25°) were recruited and consented for this IRB approved study. Gait analysis with 58 reflective markers were placed by palpation on anatomical landmarks of the torso and lower extremities. Ten optoelectronic cameras (Qualisys, Gothenburg, Sweden) and three force plates (AMTI, Watertown, MA) were used to track marker position and measure foot strike forces. Subjects walked at a self-selected speed across the force plates until ten clean trials were performed and then were scanned with the reflective markers on the spine using an EOS (EOS Imaging, France) bi-planar x-ray system. Following testing participants completed a six week stretching program to increase hamstring length. Pelvic tilt (PT) was measured at heel strike for each trial and averaged. Using EOS scans the femoral head radius was measured using three points that best fit the load bearing surface on the sagittal view from the anterior acetabular rim to a point on the posterior acetabulum 45 degrees from vertical. The radius of femoral head and angle of acetabular coverage were used to calculate the load bearing surface area of femoral head. Load on the femur was calculated using an Anybody lower body model (Anybody Technology, Aalborg, Denmark) and load per unit area change was compared. Results. Nine participants completed the stretching program and post intervention testing. PA increased in all subjects (mean ± SD) 18.8° ± 11° (p<.01). Eight of nine subjects had an increase in anterior PT at heel strike resulting in a mean change of 2.1° ± 2.9° (p<.05). The change in PT resulted in a mean surface area change of 0.63cm. 2. ± 0.77 cm. 2. (p<.05), which resulted in a mean pressure change of −57.9MPa ± 55.7MPa. Removing the one subject who decreased in anterior pelvic tilt resulted in a mean change in PT of 2.9° ± 1.2°, a mean change in surface area of 0.85cm. 2. ± 0.46 cm. 2. , and a mean pressure change of −74.4 MPa ± 27.2 MPa. (Table 1). Discussion/Conclusion. This study verified the hypothesis that functional PT is influenced significantly by tight hamstrings. Using a stretching intervention program small changes in functional PT can be elicited that may significantly decrease the force per unit area on the femoral head and possibly the risk for developing degeneration joint disease. Although our study is limited by the small number of participants it does lend one significant benefit to intervene in patients who have chronically tight hamstrings. For figures/tables, please contact authors directly.

Aims. Interest in soft tissue Radiostereometric Analysis (RSA) is rising. Previous authors have tried, with varying levels of success, to use this technique to analyse the intra-substance portion of anterior cruciate ligament (ACL) graft constructs. These methods were either prone to large amounts of marker migration, deemed unsuitable for in-vivo use or, where alternative markers such as stainless steel sutures were used, lost the inherent accuracy that made RSA an attractive tool in the first place. We describe a modification of tantalum marker balls that allows for a new method of secure fixation to soft tissue in order to accurately analyse stretch, displacement and, potentially, dynamic movement using RSA. Methods. 1.5 mm tantalum tendon markers were predrilled with 0.3 mm holes, allowing them to be sutured directly to soft tissue. Using a previously described ACL graft model, the amount of marker ball migration was then analysed using RSA after cyclical loading between 20 N and 170 N at 25 Hz for 225,000 cycles. Results. None of 40 balls loosened or became detached from the tendon grafts after 225,000 cycles. Mean migration of the tendon attached marker balls was < 0.1 mm. The maximum imprecision in determining the distance between two markers as assessed by intra- and inter-observer variability was 0.082 mm. Analysis of elastic stretch, plastic stretch, stiffness and localisation of stretch within the graft model was possible due to the low migration levels. Conclusions. This method of attachment of marker beads to soft tissue is simple, reliable and mechanically sound. This technique could potentially be used not only for the post-operative assessment of ACL reconstruction, but in all areas where soft tissue RSA is of interest

Roentgen stereophotogrammetric analysis (RSA) is the most accurate radiographic technique for the assessment of three-dimensional micromotion in joints. RSA has been used previously to study the kinematics of the anterior cruciate ligament (ACL)-deficient knee and to measure knee laxity after bone-tendon-bone (BTB) reconstructions. There is no published evidence on its use in assessing hamstring grafts in vivo, in comparing hamstring versus BTB reconstruction, or in-depth analyses of graft performance. The aim of this project was to use RSA to measure laxity in both BTB and hamstring reconstructions, and to attempt a detailed analysis of graft behaviour in both reconstructions, with particular attention to graft stretching and slippage of the bony attachments. A prospective study was undertaken on 14 patients who underwent ACL reconstruction. Seven had BTB reconstruction, and seven had four-stranded semitendinosus/gracilis (STG). Tantalum markers were inserted at the time of surgery, into distal femur and proximal tibia, and also directly into the graft itself. Stress radiographs (90N anterior and 90N posterior force) were taken early post-operatively, and then at 6 weeks, and 3, 6 and 12 months. In addition to measuring total anteroposterior knee laxity, a detailed analysis of the graft itself was possible. The BTB grafts had stretched by an average of 1.54%, and the bone plugs had migrated by 0.50 mm at the femoral end and by 0.61mm at the tibial end. The hamstring grafts had stretched on average 3.94%, and the intraosseous ends had migrated by 3.96mm at the femoral end and by 7.10mm at the tibial end. This is believed to be the most detailed application of RSA in analysing the performance of the two commonly used grafts in ACL reconstruction. Details such as graft stretching and fixation slippage have not been available previously; the data obtained in this study may have implications for clinical practice

Aim. Over the last 15 years there has been a series of publications reporting the beneficial effects of elbow arthrolysis, with considerable variation in operative technique and post-operative management. Many advocate the use of passive stretching techniques in the early post-operative period if range of motion fails to improve satisfactorily. The purpose of this study was to assess our results of open elbow arthrolysis in patients who did not receive any passive stretching after discharge from hospital. Methods. Prospectively collected data of 55 patients with a minimum follow-up of 1 year after arthrolysis were analysed. All procedures were performed by the same surgeon (LR), achieving as much improvement in elbow motion as possible at operation. All patients had continuous brachial plexus blocks and continual passive motion for 2-3 days post-operatively but none received any passive stretching after discharge. At review, a senior physiotherapist (BD) formally assessed all the patients. Results. All patients' arc of movement improved from 68 degrees to 104 degrees (flexion 18 degrees/extension 23 degrees). Upper limb function (Disabilities of the Arm, Shoulder and Hand score) improved by 50%. Pain decreased from 20 to 9, measured with a Visual Analogue Score. The greatest improvement in motion was obtained in the stiffest elbows - 7 patients with an arc of 30 degrees or less pre-operatively achieved an arc of 100 degrees by the time of the last review. Conclusions. Good results of open arthrolysis for post-traumatic elbow stiffness can be achieved with continuous brachial plexus blocks and continual passive motion for 2-3 days post-operatively. There appears to be little evidence to support treatment with passive stretching techniques after discharge from hospital, as our results are similar to other reported series

The etiology of the flexion contracture is related to recurrent effusions present in a knee with end-stage degenerative joint disease secondary to the associated inflammatory process. These recurrent effusions cause increased pressure in the knee causing pain and discomfort. Patients will always seek a position of comfort, which is slight flexion. Flexion decreases the painful stimulus by reducing pressure in the knee and relaxing the posterior capsule. Unfortunately, this self-perpetuating process leads to a greater degree of contracture as the disease progresses. Furthermore, patients rarely maintain the knee in full extension. Even during the gait cycle the knee is slightly flexed. As their disease progresses, patients limit their ambulation and are more frequently in a seated position. Patients often report sleeping with a pillow under their knee or in the fetal position. All of these activities increase flexion contracture deformity. Patients with excessive deformity >40 degrees should be counseled regarding procedural complexity and that increasing constraint may be required. Patients are seen pre-operatively by a physical therapist and given a pre-arthroplasty conditioning program. Patients with excessive flexion contracture are specifically instructed on stretching techniques, as well as quadriceps rehabilitation exercises. Avoiding Pitfalls and Complications: Treating patients with flexion contracture involves a combination of bone resection and soft tissue balance. One must make every effort to preserve both the femoral and tibial joint line. In flexion contracture the common error is to begin by resecting additional distal femur, which may result in joint line elevation and mid-flexion instability. The distal femoral resection should remove that amount of bone being replaced with metal. Attention should be directed at careful and meticulous balance of the soft tissues and release of the contracted posterior capsule with re-establishment of the posterior recess, which will correct the majority of flexion contractures. Residual Flexion Contracture: Inability to achieve ROM after TKA represents a frustrating complication for both patient and surgeon. Non-operative treatments for the stiff TKA include shoe lift in contralateral limb, stationery bicycle with elevated seat position, extension bracing, topical application of hand-held instruments to areas of soft tissue-dysfunction by a trained physical therapist over several outpatient sessions, and use of a low load stretch device. Manipulation under anesthesia is indicated in patients after TKA having less than 90 degrees ROM after 6 weeks, with no progression or regression in ROM. Other operative treatments range from a downsizing exchange of the polyethylene bearing to revision with a constrained device and low-dose irradiation in cases of severe arthrofibrosis

Background. Calipered kinematically aligned (KA) total knee arthroplasty (TKA) restores the in vitro internal-external (I-E) rotation laxities at 0° and 90° of the native knee. Although increasing and decreasing the thickness of the insert in 1 mm increments loosens and tightens the flexion space, there are little data on how this might adversely affect the screw-home mechanism and I-E rotational laxity. The present study determined the differences in the I-E range of rotation and I-E positions at maximum extension and at 90° of flexion that result from the use of insert thicknesses that deviate ± 1mm in thickness from the implanted insert. Methods. 20 patients were treated with a calipered KA and a PCL retaining implant with a 1:1 medial ball-in-socket constraint and a non-constrained lateral flat articular insert surface. Verification checks, that are validated to restore native tibial compartment forces without release of healthy ligaments including the PCL, were used to select the optimal insert thickness. Trial inserts with thicknesses ranging from 10 to 13 mm were 3-D printed with medial goniometric markings that record rotation from 20° external to −20° internal with respect to a sagittal line laser marked on center of the medial condyle of the trial femoral component at maximum extension and 90° of flexion (Figure 1). Results. For all three inserts, the tibial component progressively internally rotated on the femoral component from maximum extension to maximum flexion. From maximum extension to 90° flexion the −21.7° range of internal rotation for the optimal insert thickness was greater than the −16° for the 1mm thinner insert (p < 0.000), and the −13.1° for the 1mm thicker insert (p < 0.000). At maximum extension, the mean insert position of 7° external for the optimal insert thickness was more external than the 4.5° for the 1mm thinner insert (p < 0.000), and the 3.5° for the 1mm thicker insert (p < 0.000) (Figure 2). At 90° the mean −14.7° internal insert position for the optimal insert thickness was more internal than the −11.5° for the 1mm thinner insert (p < 0.000), and the −9.5° for the 1mm thicker insert (p < 0.000) (Figure 3). Discussion and Conclusions. The insert goniometer is an inexpensive, simple, and sensitive instrument that measured the insert position of a medial ball-in-socket PCL retaining implant with a flat lateral insert implanted with calipered KA and showed the I-E rotation matched the pattern of the native knee's screw-home mechanism. Restoring the pre-arthritic native ligament laxities is the target, as the insert goniometer detected a 6° loss of internal rotation and a less external position of the insert at maximum extension and a less internal position at 90° when the healthy ligaments were stretched or loosened by 1mm. For any figures or tables, please contact the authors directly

Introduction. Iliopsoas impingement is a well described cause of groin pain after direct anterior total hip arthroplasty (THA). We proposed to evaluate the incidence, natural history and response to treatment of iliopsoas impingement after direct anterior total hip arthroplasty. Methods. A retrospective chart review of 725 consecutive patients who underwent anterior approach total hip arthroplasty between 2009 and 2014 was conducted. All surgeries were performed by one of two surgeons. Patients were included if they underwent primary anterior approach THA and had a minimum of 2 years of follow up. Patients who had a posterior approach, revision surgery or had less than 2 years of follow up were excluded. Iliopsoas impingement was identified if patients reported groin pain at greater than 6 weeks of postoperative follow up and in association with pain with resisted seated hip flexion. The natural history and response to treatment was recorded for patients identified as having iliopsoas impingement. Results. 900 patients met inclusion criteria. Of these, 120 (13.4%) developed groin pain following direct anterior total hip arthroplasty. The average time of onset was at 21 months postoperatively. At 2 years postoperatively, 16% of patients had symptoms, whereas 84% had resolution. 28% of patients responded to structured physical therapy, 22% improved with home stretching, 19% improved after arthroscopic psoas release, 9% after psoas sheath injection, and 6% required acetabular component revision. Conclusion. In our study population, iliopsoas impingement is not an uncommon finding after direct anterior total hip arthroplasty, but nearly half of these patients responded well to home stretching or physical therapy. In some cases, psoas injection and arthroscopic release was necessary. Rarely, cup revision was required for symptomatic relief

An important goal of total knee replacement is deformity correction. Arthritic narrowing can be accompanied by a fixed shortening of the collateral ligament on the same side of the narrowing. There can also be ligamentous laxity that develops in the opposite compartment. Flexion contracture can develop with tightening of the posterior capsule. Successful total knee replacement requires proper bone resection along with gap balancing and balanced collateral ligament tensioning. Beware of correctable deformities, as the collateral ligament may have kept its resting length and therefore the knee becomes stable after the bone resections are made and the spacer block is inserted to test the stability of the knee in flexion and extension. In the varus knee, the MCL may be contracted. A medial release of the superficial medial collateral ligament may be necessary. This can be done by stripping the periosteal insertion of the MCL. A stretch may be accomplished by placing a laminar spreader in the narrow medial joint space and opening the space until the MCL stretches from its insertion. This maneuver will require a further increase in polyethylene thickness height of 2 – 4mm. Krackow has also on occasion done a surgical imbrication of the LCL, if it appears attenuated on the lateral side of a severe varus deformity. For valgus deformities, the LCL, arcuate ligament and popliteus and ITB can be contracted. At this time, most authors recommend preservation of the popliteus tendon as it affects primarily the flexion gap. In extension there has been consensus that the surgeon should release what is tight. This may include the ITB release in a pie-crust fashion, or off the Gerdy's tubercle and then a selective release of the arcuate ligament complex. Krackow has also utilised tightening imbrication of the MCL if it is severely attenuated and lax. This has been used infrequently, however. To avoid overlengthening of the knee by referencing balance off of the lengthened, attenuated MCL in cases of severe valgus deformity, less release is performed and a CCK implant may be used. For severe flexion contractures, the posterior osteophytes should be first aggressively removed. The posterior joint capsule can be stripped off the distal femur and sometimes the gastrocnemius muscle insertions can be dissected free. After these maneuvers, proximal raising of the joint line by resection of the distal femur can be utilised. In ankylosis with severe flexion contracture, constrained implants will be needed if the proximal resection extends above the insertion of the collateral ligaments. Recurvatum is a rarely seen deformity that is usually associated with an extraordinarily weak or paretic quadriceps. The joint capsule has become stretched over time. Careful balancing of the knee is necessary. But, if the recurvatum still persists, distally augmenting the femur is an option. And no releases are required

Athletes involved in repetitive overhead shoulder rotation demonstrate increased external rotation and decreased internal rotation range of motion. Deficits in internal rotation have been linked to the development of shoulder pathology. The purpose of this study is to determine if a posterior shoulder stretch program is effective in increasing dominant arm internal rotation and horizontal adduction range of motion in overhead athletes identified as having reduced mobility and posterior shoulder tightness. Thirty-seven overhead athletes in volleyball, swimming and tennis, with internal rotation range of motion deficits greater than or equal to 15°, were randomised into intervention or control groups. The intervention group performed the “sleeper stretch” daily for eight weeks while the control group performed usual activities. Independent t-tests determined whether internal rotation and horizontal adduction range of motion differences between groups were significant and two-way repeated measures analysis of variance tests measured the rate of shoulder range of motion change. Reported shoulder pain and function were also obtained at each evaluation. Significant differences were found between the intervention and control groups' internal rotation and horizontal adduction range of motion at eight weeks (p<0.001 and p=0.003 respectively) compared to baseline (zero weeks) (p=0.19 and p=0.82 respectively). Significant changes in internal rotation were detected in the intervention group at four weeks (p<0.001) with further adaptations noted at eight weeks. Horizontal adduction improved at a slower rate demonstrating significant changes at eight weeks (p=0.003). Reported shoulder pain and functional ability (p=0.002) were different between the study groups at eight weeks. Overhead, collegiate-level athletes with an internal rotation deficit greater than or equal to 15° are able to significantly increase internal rotation and horizontal adduction range of motion by performing a posterior shoulder stretch exercise for eight weeks

Following arthroscopic arthrolysis for frozen shoulder, steroid injections may become necessary to improve ongoing pain and facilitate stretching exercises. The aim of this study was to evaluate the rate of steroid injections needed post-arthroscopic arthrolysis of frozen shoulder. Case series review carried out in a District General Hospital in UK. 30 consecutive patients who had arthroscopic arthrolysis under the care of the senior author were included. Patients’ records were analysed to identify the number of steroid injections administered post-operatively. 11 males and 19 females were examined, aged 46–83 years old (mean 56.1). 7 patients were diabetic. 10 patients (33.3%) received steroid injections post-operatively, with 8 of them receiving the injection within the first 6 post-operative months. The average post-operative time of steroid injection was 9.8 months. There was no association between diabetes and administration of a post-operative steroid injection P>0.01. Following arthroscopic arthrolysis a substantial proportion of patients may require one or more steroid injections to help pain and facilitate stretching exercises and physiotherapy. This study showed that 1 in 3 frozen shoulders treated with arthroscopic arthrolysis may need a subsequent steroid injection in the first year post surgery. Patients should be counselled preoperatively with regards to that, and be warned that arthroscopic arthrolysis is only the first step in the treatment pathway leading to recovery. Blackpool Victoria Hospital Orthopaedic Department

The detailed biomechanical mechanism of annulus fibrosus under abnormal loading is still ambiguous, especially at the micro and nano scales. This study aims to characterize the alterations of modulus at the nano scale of individual collagen fibrils in annulus fibrosus after in-situ immobilization, and the corresponding micro-biomechanics of annulus fibrosus. An immobilization model was used on the rat tail with an external fixation device. Twenty one fully grown 12-week-old male Sprague-Dawley rats were used in this study. The rats were assigned to one of three groups randomly. One group was selected to be the baseline control group with intact intervertebral discs (n=7). In the other two groups, the vertebrae were immobilized with an external fixation device that fixed four caudal vertebrae (C7-C10) for 4 and 8 weeks, respectively. Four K-wires were fixed in parallel using two aluminum alloy cuboids which do not compress or stretch the target discs. The immobilized discs were harvested and then stained with hematoxylin/eosin, scanned using atomic force microscopy to obtain the modulus at both nano and micro scales, and analyzed the gene expression with real-time quantitative polymerase chain reaction. Significance of differences between the study groups was obtained using a two-way analysis of variance (ANOVA) with Fisher's Partial Least-Squares Difference (PLSD) to analyze the combined influence of immobilization time and scanning region. Statistical significance was set at P≤0.05. Compared to the control group, the inner layer of annulus fibrosus presented significant disorder and hyperplasia after immobilization for 8 weeks, but not in the 4 week group. The fibrils in inner layer showed an alteration in elastic modulus from 91.38±20.19MPa in the intact annulus fibrosus to 110.64±15.58MPa (P<0.001) at the nano scale after immobilization for 8 weeks, while the corresponding modulus at the micro scale also underwent a change from 0.33±0.04MPa to 0.47±0.04MPa (P<0.001). The upregulation of collagen II from 1±0.03 in control to 1.22±0.03 in 8w group (P = 0.003) was induced after immobilization, while other genes expression showed no significant alteration after immobilization for both 4 and 8 weeks compared to the control group (P>0.05). The biomechanical properties at both nano and micro scales altered in different degrees between inner and outer layers in annulus fibrosus after immobilization for different times. Meanwhile, the fibril arrangement disorder and the upregulation of collagen II in annulus fibrosus were observed using hematoxylin/eosin staining and real-time RT-PCR, respectively. These results indicate that immobilization not only influenced the individual collagen fibril at the nano scale, but also suggested alterations of micro-biomechanics and cell response. This work provides a better understanding of IVD degeneration after immobilization and benefits to the clinical treatment related to disc immobilization

Introduction. Revision for instability has supplanted revision for aseptic loosening and revision for osteolysis since the advent of improved polyethylene inserts with changes in both sterilization techniques and cross-linking. Having the ability to judiciously choose a higher level of constraint may be beneficial in complex primary total knee arthroplasty (TKA) scenarios which can not be balanced through traditional surgical methods. The purpose of this work was to investigate short term outcomes and survivorship in cases where a greater stabilizing insert was used with a posterior stabalizing (PS) femur to address instability in flexion or extension. Methods. Two high volume TKA centers retrospectively reviewed cases in which a greater stabilizer insert was used with a primary PS knee system. The studied insert had +/− 2 degrees of varus-valgus coronal restraint as opposed the standard with no coronal constraint. The study inserts had 7 degrees of transverse plane rotational freedom. The inserts were used when extension balance was not achieved despite the usual soft tissue releases and a thicker insert resulted in a flexion contracture statically during the procedure. This situation typically occurred in the following patient groups: valgus knees with medial collateral (MCL) stretching, iatrogenic MCL injury, varus knees with lateral ligament complex stretching, the “double-varus” knee, and patients with a previous high tibial osteotomy. Intra-operatively patients were taken through a range of motion and trial implants were then placed. A cruciate retaining trial insert was then used to assess stability so that a true assessment could be made of ligament balance. Bone cuts were checked before ligament release. The usual releases were then performed to achieve balance including subperiosteal releases medially and laterally and pie-crusting when indicated. Repeat trial reductions were then performed once the final implants were cemented in place again using the cruciate retaining insert. If the soft tissue releases did not achieve balance and a thicker insert resulted in a flexion contracture then the greater stabilizer insert was selected over the PS insert. Knee Society Score and plain radiographs were collected at pre-op, 2 year and 5 year follow-up. Results. One hundred seventy two cases with 2 year minimum follow-up and 41 cases with 5 year minimum follow up were assessed. All patients had good to excellent Knee Society Scores with good range of motion and pain relief. There were no aseptic revisions of the TKA's over this period. Specifically, there were no revisions for loosening, osteolysis, instability, or post breakage. Conclusions. A more stabilized tibial post insert which provides valgus-varus constraint but permits rotational freedom may provide needed stability in select primary situations without predisposing to early post failure or implant loosening or lysis

This study documents the gross and histologic structure of the infrapatellar plica, and fat pad, and adds to an earlier report to the COA. The important new findings are that the femoral attachment of the plica is an enthesis, and that the plica itself is. This study seeks to demonstrate that the structure of the fat pad (FP) and infrapatellar plica (IPP) is that of an enthesis organ. Twelve fresh frozen cadaver knees, each with an IPP, were dissected and the gross anatomic features recorded. The IPP and FP were harvested for study. Representative histologic sections were prepared on tissue fixed in 10% neutral buffered formalin, embedded in paraffin, cut at 4 microns on a rotatory microtome. Staining techniques included hematoxylin and eosin, Masson's trichrome, elastic stain and S100. Appropriate decalcification of sections of the femoral insertion of the IPP was performed. All sections were examined by light microscopy at low, medium and high power. IPP types included 8 separate, 1 split, 2 fenestrated, and one vertical septum. The origin of the IPP is a fibrous arc arising from the apex of the notch separate from the margin of the articular cartilage. This attachment site is the instant centreof rotation of the IPP and FP; they are thus not isometric. The central zone of the IPP consists of a mix of connective tissue types. Representative sections taken of the femoral attachment of the IPP display a transition zone between dense fibrillar collagen of the IPP, then fibrocartilage and cortical bone similar to a ligament attachment site or enthesis. The central plica histology is composed predominantly of dense regular connective tissue with variable clear space between the collagen bundles, and is thus ligamentous. There is abundant elastase staining throughout, as well as crimping of the collagen suggesting capacity for stretch. S100 staining demonstrates nerves around and in the substance of the IPP. The central body shows lobulated collections of mature adipose tissue admixed with loose connective tissue, containing abundant small peripheral nerves and vessels (all showing crimping and redundancy), merging with the dense fibrous tissue of the IPP. The FP is highly innervated, deformable, and fibro-fatty. Its histology shows lobules of fat, separated by connective tissue septa, which merge with the synovial areolar membrane surrounding the FP. The linked structures, IPP, central body, and FP occupy the anterior compartment, and function as an enthesis organ: the IPP tethers the FP via the central body and together they rotate around the femoral origin of the IPP. They are not isometric, and must stretch and relax with knee motion. The histology correlates with this requirement. The origin of the IPP is an enthesis, a new observation. Elastase staining, redundancy of vessels and nerves, crimping and redundancy of the dense connective tissue all reflect the requirement to deform. The fat pad merges with the central body, both highly innervated space fillers, tethered by the IPP, which is a non-isometric ligament, also containing nerves. The important clinical significance of these structures is that release of the IPP at the origin reuces or eliminates anterior knee pain in most

Valgus deformity is less common than varus. There is an associated bone deformity in many cases – dysplasia of the lateral femoral condyle. There are also soft tissue deformities, including tightness of the lateral soft tissues, and stretching of those on the medial side. Unlike varus, where the bone deformity is primarily tibial, in valgus knees it is most often femoral. There is both a distal and a posterior hypoplasia of the lateral femoral condyle. This results in a sloping joint line, and failure to correct this results in valgus malalignment. Posterior lateral bone loss also results in accidental internal rotation of the femoral component, which affects patellar tracking. Using the trans-epicondylar axis and Whiteside's line helps to position the femoral component in the correct rotation. Soft tissue balancing is more complex in the valgus knee. Releases are performed sequentially, depending on the particular combination of deformities. It is important to note whether the knee is tight in flexion, in extension, or both. Tightness in extension is the most common, and is corrected by release of the iliotibial band. Tightness in flexion as well as extension requires that the lateral collateral ligament +/− the popliteus tendon be released. Cruciate substituting designs are helpful in many cases, and in extreme deformity with medial stretching, a constrained or “total stabilised” design is needed. Patellar maltracking is common, and a lateral retinacular release may be needed. Beware of over-releasing the posterolateral corner, as excessive release may cause marked instability. Use the pie-crust technique of Insall

Chronic extensor mechanism insufficiency around TKA is a very challenging pathology to treat. An insufficient extensor mechanism negatively affects implant survival and patient outcomes. There are several risk factors for extensor mechanism disruption and the surgeon should be aware and avoid these problems in the perioperative period. In appropriately selected patients, reconstruction of the extensor mechanism is a valid option. Whole extensor mechanism and Achilles tendon allograft reconstruction of the deficient extensor mechanism have been proposed with good early published results. These reconstructions, however, are expensive and with time may stretch and lead to recurrence of an extensor lag. An alternative to allograft, is the use of Marlex mesh as popularised by Browne and Hanssen. This technique uses a knitted monofilament polypropylene mesh that is secured to the patient's native lateral tissue and covered by an appropriately dissected and distalised vastus medialis muscle. The technique can be used for both patellar and quadriceps tendon deficiencies and can be done with or without implant revision and is currently the treatment of choice at the presenter's institution. The surgeon should be aware of the complexity and limitations of these three reconstructive techniques

During the therapy of infected pseudarthrosis and arthrodesis in which multiple autologous bone grafts did not result in osseous consolidation and in delayed osseous healing of transport stretches after completion of segmental transport in osteomyelitis patients without acute infection symptoms, mesenchymal stem cells were added to the treatment. This study demonstrates the mid- and long-term results in different application possibilities with good and poor results. The aim is to develop an algorithm in treating bone defects regarding the different biomaterials and implants that exist on the market. The indication to apply mesenchymal stem cells was the reconstruction of osseous lesions after chronic osteomyelitis, the treatment of pseudarthrosis and the support of osseous growth in segmental transports. Further indications were the absence of adequate amounts of autologous spongiosa, multiple previous operations, risk factors (diabetes, peripheral vascular disease, alcohol and nicotine abuse, etc.) as well as chronic wound healing failure. To obtain the mesenchymal stem cells, we employed two different systems from two companies. Both systems concentrate the mesenchymal stem cells after puncture and aspiration from the pelvic crest. The concentrated stem cells were either mixed with platelet-rich plasma and added to the autologous spongiosa or injected into the area of osseous regeneration after completion of segment transport. Since 2009, we have applied mesenchymal stem cells to 87patients. The treatment was performed in 73 cases of persisting pseudarthrosis after multiple bone grafts and in 14 cases of delayed osseous healing after segmental transport. The results were evaluated by continuous clinical and radiological examinations in our outpatient clinic. We found a great variety in our results with a mainly high rate of survival and healing in the autologous bone grafts with mesenchymal stem cells, resulting predominantly in stabilization of the pseudarthrosis. Furthermore a good osseous consolidation was documented in several cases with transport stretches of segmental transports. However we also had some frustrating results with all the well-known complications of septic surgery. Our experiences so far, have led to a distinguished therapy-algorithm including all the biomaterials and additives that are used in our hospital. Overall, the results demonstrate an advantage in the treatment with mesenchymal stem cells, espe-cially in problematic and difficult cases in combination with multiple pre-existing conditions. The use of mesenchymal stemcells must be included in a general concept regarding all treatment possibilities, it is, however, not a guarantee for successful therapy of osseous lesions after chronic osteomyelitis especially as a single toll mechanism