Prevalence of extra-articular tibia valga morphology in valgus knees and its implications for primary total knee arthroplasty.

INTRODUCTION: Tibia valga, an extra-articular valgus deformity of the tibia, is common in valgus knees and can result in component misplacement and early total knee arthroplasty (TKA) failure. However, the prevalence and importance of tibia valga in TKA have been seldom reported. This study aims to describe the prevalence and characteristics of tibia valga morphology in valgus knees and describe implications for surgical planning in primary TKA. METHODS: We prospectively examined pre-operative weightbearing whole-body EOS digital radiographs of patients with knee osteoarthritis listed for TKA between December 2018 and December 2020. Hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), joint line convergence angle (JLCA) and tibial morphology with centre of rotation of angulation of tibia (CORA-tibia) were measured and analysed. RESULTS: In 830 knees, 253 (30%) and 577 (70%) were classified as valgus and varus, respectively. In valgus knees, 89 knees (35%) had tibia valga. Median CORA-tibia was 2.8° (range 0.2°-10.9°). Tibia valga knees had no difference in mLDFA, higher HKA (5.0o versus 3.0°, p = 0.002) and mMPTA (89.6° versus 88.1°, p < 0.01), and lower JLCA (2.1° versus 2.3°, p < 0.01) compared to non-tibia valga knees. Tibia valga deformity was weakly positively correlated with valgus HKA (ρ = 0.23, p < 0.001) and mMPTA (ρ = 0.38, p < 0.001). In varus knees, there were 52 cases of tibia valga (9%) with median CORA-tibia of 3.0° (range 0.5°-5.5°). Tibia valga knees had higher mMPTA (87.0° versus 85.2°, p < 0.05) and no difference in HKA, mLDFA and JLCA. CORA-tibia was weakly positively correlated with mMPTA. CONCLUSIONS: Valgus knees may have an extra-articular deformity of the tibia which might be the primary contributor of the overall valgus HKA deformity rather than the distal femoral anatomy. To detect the deformity, full leg-length radiographs should be acquired pre-operatively. Intramedullary instrumentation should be used cautiously in knees with tibia valga when performing TKA.

Anterior approach to hip replacement and associated complications: an independent review.

BACKGROUND: Direct anterior approach (DAA) to hip replacement is increasingly popular. Despite the well-published benefits of early recovery, the approach can be associated with a number of complications that may be underreported. We aim to report the incidence of some of these complications in a large retrospective case series. METHODS: 270 consecutive DAA hip replacements are studied which are performed by a single high-volume hip surgeon from 2013 to 2015, not including the surgeon's learning curve. Operation and consultation records were screened, and focused questioning via telephone was employed to capture specific complications including dislocations, wound infections, lateral femoral cutaneous nerve (LFCN) injury and revision surgery. RESULTS: 240 of 270 patients or family were contactable. The mean age and body mass index of the cohort was 66 (range 30-89) years and 27 (range 18-40) kg/m2 respectively. The mean follow-up was 3.7 years. Wound issues were encountered in 24 patients (8.8%). There were 9 dislocations (3%). 27 (10%) patients needed revision surgery in the follow-up period. Reasons for revision included leg-length discrepancies, dislocations, ongoing pain and aseptic loosening. 9 (3.4%) patients had to return to operating theatre for reasons other than revision surgery. Symptoms of lateral femoral cutaneous nerve injury was reported by 54 patients (21%). CONCLUSIONS: While the short-term benefits of DAA have been widely reported, our review shows a relatively high rate of revision surgery. We feel that the enthusiasm for DAA should be tempered until further evidence is available.

Accuracy of one-dimensional templating on linear EOS radiography allows template-directed instrumentation in total knee arthroplasty.

BACKGROUND: Templating for total knee arthroplasty (TKA) is routinely performed on two-dimensional standard X-ray images and allows template-directed instrumentation. To date, there is no report on one-dimensional (1D) anteroposterior (AP) templating not requiring specific templating software. We aim to describe a novel technique and explore its reliability, accuracy and potential cost-savings. METHODS: We investigated a consecutive series of TKAs at one institution between January and July 2019. Patients with preoperative low-dose linear AP EOS radiography images were included. Implant component sizes were retrospectively templated on the AP view with the hospitals imaging viewing software by two observers who were blinded to the definitive implant size. Planning accuracy as well as inter- and intra-observer reliability was calculated. Cost-savings were estimated based on the reduction of trays indicated by the 1D templating size estimations. RESULTS: A total of 141 consecutive TKAs in 113 patients were included. Accuracy of 1D templating was as follows: exact match in 53% femoral and 63% tibial components, within one size in 96% femoral and 98% tibial components. Overall 58% of TKA components were planned correctly and 97% within one size. Inter- and intra-rater reliability was good (κ = 0.66) and very good (κ = 0.82), respectively. This templating process can reduce instrumentation from six to three trays per case and therefore halve sterilisation costs. CONCLUSIONS: The new 1D templating method using EOS AP imaging predicts component sizes in TKA within one size 97% of the time and can halve the number of instrumentation trays and sterilisation costs.

Erector spinae plane block combined with local infiltration analgesia for total hip arthroplasty: A randomized, placebo controlled, clinical trial.

The erector spinae plane block is an emerging analgesic technique, which is gaining popularity for a large number of procedures. The majority of publications are at the thoracic level and almost all indicate some benefit to patients. However, there have been relatively few randomized controlled trials and even fewer studies at the lumbar level. The aim of this study was to assess whether the erector spinae plane block at the lumbar level would confer early analgesic benefits and improve the quality of recovery in patients undergoing elective unilateral primary hip arthroplasty. Sixty-four patients were randomized to receive an erector spinae plane block at the third lumbar vertebra with either 30milliliters (ml) of 0.2% ropivacaine or 30 ml of 0.9% saline. The patient, anesthetist and assessor were blinded to allocation. The primary outcome was pain on movement at 6 h (numeric rating scale 0-10) with a reduction of 2 points considered clinically significant. Secondary outcomes included quality of recovery (QoR-15 score), mobilization and length of stay. In this study there was no appreciable analgesic benefit to adding an erector spinae plane block to patients who already receive neuraxial blocks, local anesthetic infiltration and oral multimodal analgesia for elective primary total hip arthroplasty. Both groups were found to have relatively low pain scores and a high quality of recovery with no significant difference in mobilization or length of stay.

Wavelength weightings in machine learning for ovine joint tissue differentiation using diffuse reflectance spectroscopy (DRS).

Objective: To investigate the DRS of ovine joint tissue to determine the optimal optical wavelengths for tissue differentiation and relate these wavelengths to the biomolecular composition of tissues. In this study, we combine machine learning with DRS for tissue classification and then look further at the weighting matrix of the classifier to further understand the key differentiating features. Methods: Supervised machine learning was used to analyse DRS data. After normalising the data, dimension reduction was achieved through multiclass Fisher's linear discriminant analysis (Multiclass FLDA) and classified with linear discriminant analysis (LDA). The classifier was first run with all the tissue types and the wavelength range 190 nm - 1081 nm. We analysed the weighting matrix of the classifier and then ran the classifier again, the first time using the ten highest weighted wavelengths and the second using only the single highest. Our method was applied to a dataset containing ovine joint tissue including cartilage, cortical and subchondral bone, fat, ligament, meniscus, and muscle. Results: It achieved a classification accuracy of 100% using the wavelength 190 nm - 1081 nm (2048 attributes) with an accuracy of 90% being present for 10 attributes with the exception of those with comparable compositions such as ligament and meniscus. An accuracy greater than 70% was achieved using a single wavelength, with the same exceptions. Conclusion: Multiclass FLDA combined with LDA is a viable technique for tissue identification from DRS data. The majority of differentiating features existed within the wavelength ranges 370-470 and 800-1010 nm. Focusing on key spectral regions means that a spectrometer with a narrower range can potentially be used, with less computational power needed for subsequent analysis.

Cementless Versus Cemented Tibial Fixation in Posterior Stabilized Total Knee Replacement: A Randomized Trial.

BACKGROUND: Evidence supports the use of cementless tibial component fixation in total knee replacement but there is a paucity of literature on posterior stabilized designs. This randomized study of posterior stabilized total knee replacements compared cemented and cementless tibial fixation with regard to component migration, bone remodeling, and clinical outcomes. METHODS: This prospective single-center, blinded, randomized clinical trial included 100 patients with a mean age of 68 years (range, 45 to 87 years). Operations were performed by either of 2 experienced arthroplasty surgeons using the Advanced Coated System (ACS) prosthesis (Implantcast). Patients were randomized to cemented or cementless tibial fixation; other variables were standardized. Radiostereometric analysis (RSA) and dual x-ray absorptiometry (DXA) were performed during the inpatient stay and at 3, 12, and 24 months to monitor tibial component migration and periprosthetic bone mineral density (BMD). Clinical scores including the Oxford Knee Score and Short Form-12 were assessed prior to surgery and during follow-up. RESULTS: Late and continuing migration was found with cementless fixation. At 24 months, the mean subsidence was significantly greater for the cementless group (1.22 mm) compared with the cemented group (0.06 mm) (p < 0.01). The mean maximum total point motion at 24 months was 2.04 mm for the cementless group and 0.48 mm for the cemented group (p < 0.01). The cemented group had more BMD loss than the cementless group in the medial, lateral, and anterior periprosthetic regions. Two tibial components were revised in the cementless group, including 1 for loosening. Clinical scores improved equally in the 2 groups. CONCLUSIONS: Late ongoing subsidence and high maximum total point motion in our patients who underwent cementless tibial fixation raise concerns about the fixation stability of ACS cementless posterior stabilized knee replacements. Cemented tibial components were stable. Thus, we advise caution regarding the use of cementless tibial components and recommend tibial fixation with cement for the ACS posterior stabilized total knee replacement. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

'My hip is damaged': a qualitative investigation of people seeking care for persistent hip pain.

OBJECTIVES: Clinicians who use the biopsychosocial approach to manage musculoskeletal pain disorders aim to understand how patients make sense of their symptoms. Treatment includes targeting the negative beliefs and coping responses that can lead to progressive pain and disability. We aimed to explore how people seeking care for persistent hip pain and disability make sense of their symptoms. METHODS: Cross-sectional qualitative study. People were eligible if they were aged ≥18 years, were consulting an orthopaedic surgeon for persistent hip pain and offered a non-surgical intervention. Data were collected through interviews that explored patients' beliefs about the identity (diagnosis), causes, consequences, timeline and controllability of their symptoms, their strategies to cope with pain and their experiences in seeking healthcare. Transcribed interview data were analysed thematically using a framework approach. RESULTS: Sixteen people (median age=51, range=33-73 years; median duration hip pain=3 years, range=3 months-20 years) participated. Most participants (10/16) believed their pain was caused by an exercise-related injury. Because of the results of imaging and interactions with healthcare professionals, all participants believed they had damaged hip structures. All described ineffective strategies to manage their pain and multiple failed treatments. For many (7/16), a lack of control over symptoms threatened their physical and mental health. CONCLUSIONS: The way participants with persistent hip pain and disability made sense of their symptoms contributed to them avoiding physical activity, and it impaired their sleep, emotional well-being and physical health.

Thermal Assessment of Ex Vivo Laser Ablation of Cortical Bone.

As a potential osteotomy tool, laser ablation is expected to provide rapid machining of bone, while generating minimal thermal damage (carbonization) and physical attributes within the machined region conducive to healing. As these characteristics vary with laser parameters and modes of laser operation, the clinical trials and in vivo studies render it difficult to explore these aspects for optimization of the laser machining parameters. In light of this, the current work explores various thermal and microstructural aspects of laser-ablated cortical bone in ex vivo study to understand the fundamentals of laser-bone interaction using computational modeling. The study employs the Yb-fiber Nd:YAG laser (λ = 1064 nm) in the continuous wave mode to machine the femur section of bovine bone by a three-dimensional machining approach. The examination involved thermal analysis using differential scanning calorimetry and thermogravimetry, phase analysis using X-ray diffractometry, qualitative analysis using X-ray photoelectron spectroscopy, and microstructural and semiquantitative analysis using scanning electron microscopy equipped with energy-dispersive spectrometry. The mechanism of efficient bone ablation using the Nd:YAG laser was evaluated using the computational thermokinetics outcome. The use of high laser fluence (10.61 J/mm2) was observed to be efficient to reduce the residual amorphous carbon in the heat-affected zone while achieving removal of the desired volume of the bone material at a rapid rate. Minimal thermal effects were predicted through computational simulation and were validated with the experimental outcome. In addition, this work reveals the in situ formation of a scaffold-like structure in the laser-machined region which can be conducive during healing.

Evolution of surface morphology of Er:YAG laser-machined human bone.

The extensive research on the laser machining of the bone has been, so far, restricted to drilling and cutting that is one- and two-dimensional machining, respectively. In addition, the surface morphology of the laser machined region has rarely been explored in detail. In view of this, the current work employed three-dimensional laser machining of human bone and reports the distinct surface morphology produced within a laser machined region of human bone. Three-dimensional laser machining was carried out using multiple partially overlapped pulses and laser tracks with a separation of 0.3 mm between the centers of consecutive laser tracks to remove a bulk volume of the bone. In this study, a diode-pumped pulse Er:YAG laser (λ = 2940 nm) was employed with continuously sprayed chilled water at the irradiation site. The resulting surface morphology evolved within the laser-machined region of the bone was evaluated using scanning electron microscopy, energy dispersive spectroscopy, and X-ray micro-computed tomography. The distinct surface morphology involved cellular/channeled scaffold structure characterized by interconnected pores surrounded by solid ridges, produced within a laser machined region of human structural bone. Underlying physical phenomena responsible for evolution of such morphology have been proposed and explained with the help of a thermokinetic model.

The Influence of Obesity on Hip Pain, Function, and Satisfaction 10 Years Following Total Hip Arthroplasty.

BACKGROUND: The prevalence of obesity is rising, and increasing numbers of joint arthroplasty surgeries are being performed on obese patients. Concern exists that obesity increases surgical risk; however, its impact on function following total hip arthroplasty (THA) is inconsistently affirmed and less understood. A paucity exists in the literature pertaining long-term objective functional measures. Therefore, we investigated the impact of obesity on hip pain, function, and satisfaction 10 years following THA. METHODS: This single-center, prospective, observational study categorized consecutive THA patients according to their body mass index to nonobese (<30 kg/m2) and obese (≥30 kg/m2) groups. Preoperative assessment included a numerical pain rating and the Oxford Hip Score. These were repeated along with a 6-minute walk test and a Likert satisfaction scale at 3 months, 1, 5, and 10 years postoperatively. RESULTS: The series included 191 primary THA patients. No significant differences were found in hip pain or function between the obese and nonobese groups. Obese patients however had poorer walking capacity (P = .008), were more likely to use walking aids (P = .04), and were less satisfied (P = .04) at 10 years. CONCLUSION: THA confers significant long-term symptom resolution irrespective of obesity; however, despite undergoing surgery, obese patients can be counseled they may not be as satisfied as or achieve the same walking capacity as nonobese individuals.

Machine learning classification of human joint tissue from diffuse reflectance spectroscopy data.

Objective: To assess if incorporation of DRS sensing into real-time robotic surgery systems has merit. DRS as a technology is relatively simple, cost-effective and provides a non-contact approach to tissue differentiation. Methods: Supervised machine learning analysis of diffuse reflectance spectra was performed to classify human joint tissue that was collected from surgical procedures. Results: We have used supervised machine learning in the classification of a DRS human joint tissue data set and achieved classification accuracy in excess of 99%. Sensitivity for the various classes were; cartilage 99.7%, subchondral 99.2%, meniscus 100% and cancellous 100%. Full wavelength range is required for maximum classification accuracy. The wavelength resolution must be larger than 8nm. A SNR better than 10:1 was required to achieve a classification accuracy greater than 50%. The 800-900nm wavelength range gave the greatest accuracy amongst those investigated Conclusion: DRS is a viable method for differentiating human joint tissue and has the potential to be incorporated into robotic orthopaedic surgery.

Randomised clinical trial assessing migration of uncemented primary total hip replacement stems, with and without autologous impaction bone grafting.

PURPOSE: Uncemented stems in primary total hip replacement (THR) are concerning in the elderly due to ectatic femoral canals and cortical thinning resulting in higher incidence of fracture and subsidence in this population. To obviate this concern, the authors developed a technique using autologous impaction bone grafting to achieve a better fitting femoral stem. The aim of this randomised clinical trial was to assess the efficacy of the technique. METHODS: From 2013 to 2015, a total of 98 consecutive participants (100 primary THR procedures) were inducted into a single-institution, single-blinded, randomised clinical trial assessing, with radiostereometric analysis (RSA), the efficacy of autologous impaction bone grafting in uncemented primary THR compared with traditional uncemented primary THR technique. The primary outcome measure was femoral component migration using RSA. Secondary outcomes were post-operative proximal femoral bone density (using DEXA), hip function and quality of life using Oxford Hip Score (OHS) and Short Form-12 Health Survey (SF-12), hip pain and patient satisfaction. RESULTS: There was no difference in femoral component stability (p > 0.5) or calcar resorption between the Graft and No Graft Groups at two years. There was also no difference in OHS, SF-12, pain or satisfaction between the Graft and No Graft Groups at two years (p > 0.39). CONCLUSIONS: Autologous impaction bone grafting in uncemented primary THR has shown its short-term post-operative outcomes to be equivalent to standard uncemented technique, whilst offering a better fit in patients who are between femoral stem sizes. AUSTRALIAN CLINICAL TRIAL REGISTRATION NUMBER: ACTRN12618000652279.

Factors influencing return to work after hip and knee arthroplasty.

BACKGROUND: A substantial proportion of patients undergoing lower limb arthroplasty are of working age. This study aims to identify when patients return to work (RTW) and if they return to normal hours and duties, and to identify which factors influence postoperative RTW. The hypothesis is that there is no difference in time of RTW between the different types of surgery, and no difference in time of RTW based on the physical demands of the job. MATERIALS AND METHODS: Consecutive patients aged < 65 years who had undergone unilateral primary total hip arthroplasty (THA), total knee arthroplasty (TKA), or medial unicompartmental knee arthroplasty (UKA) from 2015 to 2017 were sent a questionnaire. Quantitative questions explored timing and nature of RTW, and qualitative questions explored factors influencing timing of RTW. RESULTS: There were 116 patients (64 male, 52 female) with an average age of 56 years. Thirty-one patients were self-employed and 85 were employees. Of these patients, 58 had undergone THA, 31 had undergone TKA, and 27 had undergone UKA. One hundred and six (91%) patients returned to work. Patients returned to work after (mean) 6.4 weeks (THA), 7.7 weeks (TKA), and 5.9 weeks (UKA). Time of RTW was not significantly influenced by type of surgery (p = 0.18) (ns). There was a non-significant correlation between physical demands of the work versus time of RTW (p = 0.28) (ns). There was a significantly earlier time of RTW if flexible working conditions were resumed (p = 0.003). Active recovery, motivation, necessity and job flexibility enabled RTW. The physical effects of surgery, medical restrictions and work factors impeded RTW. CONCLUSION: The time of RTW was not significantly influenced by the type of operation or by the physical demands of the job. Patients returned to work 5.9-7.7 weeks after hip/knee arthroplasty. Rehabilitation, desire, and necessity promoted RTW. Pain, fatigue and medical restrictions impeded RTW. LEVEL OF EVIDENCE: 3.

Smartphone technology: a reliable and valid measure of knee movement in knee replacement.

Knee range of motion (ROM) following a knee arthroplasty is an important clinical outcome that directly relates to the patient's physical function. Smartphone technology has led to the creation of applications that can measure ROM. The aim was to determine the concurrent reliability and validity of the photo-based application 'Dr Goniometer' (DrG) compared with a universal goniometer performed by a clinician. A smartphone camera was used to take photographs of the knee in full flexion and full extension, and the images were sent by participants to a study phone. Participants then rated the ease of participation. To assess validity, the patient's knee was measured by a clinician using a goniometer. To examine reliability, four clinicians assessed each image using DrG on four separate occasions spaced 1 week apart. A total of 60 images of knee ROM for 30 unicondylar or total knee arthroplasty were assessed. The goniometer and DrG showed strong correlations for flexion (r=0.94) and extension (r=0.90). DrG showed good intrarater reliability and excellent inter-rater reliability for flexion (intraclass correlation coefficient=0.990 and 0.990) and good reliability for extension (intraclass correlation coefficient=0.897 and 0.899). All participants found the process easy. DrG was proven to be a valid and reliable tool in measuring knee ROM following arthroplasty. Smartphone technology, in conjunction with patient-reported outcomes, offers an accurate and practical way to remotely monitor patients. Benefit may be found in differentiating those who need face-to-face clinical consult to those who do not.

Integrated experimental and computational approach to laser machining of structural bone.

This study describes the fundamentals of laser-bone interaction during bone machining through an integrated experimental-computational approach. Two groups of laser machining parameters identified the effects of process thermodynamics and kinetics on machining attributes at micro to macro. A continuous wave Yb-fiber Nd:YAG laser (wavelength 1070 nm) with fluences in the range of 3.18 J/mm2-8.48 J/mm2 in combination of laser power (300 W-700 W) and machining speed (110 mm/s-250 mm/s) were considered for machining trials. The machining attributes were evaluated through scanning electron microscopy observations and compared with finite element based multiphysics-multicomponent computational model predicted values. For both groups of laser machining parameters, experimentally evaluated and computationally predicted depths and widths increased with increased laser energy input and computationally predicted widths remained higher than experimentally measured widths whereas computationally predicted depths were slightly higher than experimentally measured depths and reversed this trend for the laser fluence >6 J/mm2. While in both groups, the machining rate increased with increased laser fluence, experimentally derived machining rate remained lower than the computationally predicted values for the laser fluences lower than ∼4.75 J/mm2 for one group and ∼5.8 J/mm2 for other group and reversed in this trend thereafter. The integrated experimental-computational approach identified the physical processes affecting machining attributes.

Patient Dissatisfaction Following Total Knee Arthroplasty: A Systematic Review of the Literature.

BACKGROUND: Dissatisfaction following total knee arthroplasty (TKA) is common. Approximately 20% of patients report dissatisfaction following primary TKA. This systematic literature review explores key factors affecting patient dissatisfaction following TKA. METHODS: Six literature databases published between 2005 and 1 January 2016 were searched using 3 key search phrases. Papers were included if the study investigated patient dissatisfaction in primary unilateral or bilateral TKA. Information from each article was categorized to the domains of socioeconomic, preoperative, intraoperative, and postoperative factors affecting patient dissatisfaction. RESULTS: This review found that patient dissatisfaction pertains to several key factors. Patient expectations prior to surgery, the degree of improvement in knee function, and pain relief following surgery were commonly cited in the literature. Fewer associations were found in the socioeconomic and surgical domains. CONCLUSION: Identifying who may be dissatisfied after their TKA is mystifying; however, we note several strategies that target factors whereby an association exists. Further research is needed to better quantify dissatisfaction, so that the causal links underpinning dissatisfaction can be more fully appreciated and strategies employed to target them.

A review of the physiological and histological effects of laser osteotomy.

Osteotomy is the surgical cutting of bone. Some obstacles to laser osteotomy have been melting, carbonisation and subsequent delayed healing. New cooled scanning techniques have resulted in effective bone cuts without the strong thermal side effects, which were observed by inappropriate irradiation techniques with continuous wave and long pulsed lasers. With these new techniques, osteotomy gaps histologically healed with new bone formation without any noticeable or minimum thermal damage. No significant cellular differences in bone healing between laser and mechanical osteotomies were noticed. Some studies even suggest that the healing rate may be enhanced following laser osteotomy compared to conventional mechanical osteotomy. Additional research is necessary to evaluate different laser types with appropriate laser setting variables to increase ablation rates, with control of depth, change in bone type and damage to adjacent soft tissue. Laser osteotomy has the potential to become incorporated into the armamentarium of bone surgery.

Tibial Tubercle Osteotomy in Revision Knee Arthroplasty.

BACKGROUND: Obtaining adequate exposure while maintaining the integrity of the extensor mechanism is crucial to the success of revision knee arthroplasty. This is particularly important in infected cases where staged procedures are necessary. While the use of a long, tibial tubercle osteotomy (TTO) is an established method to improve exposure, controversy still exists concerning complication rates and sequential use. METHODS: Forty-two TTOs were performed in revision knee arthroplasties between 2009 and 2015. Follow-up period ranged from 3 to 24 months. Twenty-four TTOs were performed for single-stage revisions, and 18 TTOs were performed for 2-stage infected revisions. In infected cases, the initial osteotomy was left unfixed between stages. Screws were used to fix the osteotomy flap in all cases. RESULTS: All osteotomies united with no fractures, and there were no extensor lags. Minor proximal migration was noted in 1 case, and refixation was required in another. Greater range of motion (ROM) and improved Oxford Knee Scores were achieved in the single-stage revision group. In the infected 2-stage group, sequential use did not decrease union rates, and infection was eradicated in 14 of the 16 knees (88%). CONCLUSION: We conclude that TTO is a safe and reproducible procedure when exposure needs improving in revision knee arthroplasty. In 2-stage revisions, sequential osteotomies do not decrease union rates, and leaving the osteotomy unfixed after the first stage does not cause any adverse issues.

A Systematic Review of Rehabilitation Exercises to Progressively Load the Gluteus Medius.

CONTEXT: Gluteus medius rehabilitation is of critical importance given its role in pelvic and lower limb stability, and the known link between gluteus medius weakness and many lower limb conditions. OBJECTIVE: To systematically review the literature and present an evidence-based graduated series of exercises to progressively load gluteus medius. EVIDENCE ACQUISITION: A systematic literature search was conducted in January 2016 to identify studies reporting gluteus medius muscle activity as a percentage of maximal volitional isometric contraction (MVIC), during rehabilitation exercises. Studies that investigated injury free participants were included. No restrictions were placed on the type or mode of exercise, though exercises that could not be accurately replicated or performed within an independent setting were excluded. Studies that did not normalize electromyographic activity to a side lying MVIC were excluded. Exercises were stratified based on exercise type and %MVIC: low (0% to 20%), moderate (21% to 40%), high (41% to 60%), and very high (> 61%). EVIDENCE SYNTHESIS: 20 studies were included in this review, reporting outcomes in 33 exercises (and a range of variations of the same exercise). Prone, quadruped, and bilateral bridge exercises generally produced low or moderate load. Specific hip abduction/rotation exercises were reported as moderate, high, or very high load. Unilateral stance exercises in the presence of contralateral limb movement were often high or very high load activities, while high variability existed across a range of functional weight-bearing exercises. CONCLUSIONS: This review outlined a series of exercises commonly employed in a rehabilitation setting, stratified based on exercise type and the magnitude of gluteus medius muscular activation. This will assist clinicians in tailoring gluteus medius loading regimens to patients, from the early postoperative through to later stages of rehabilitation.

Patient-specific instrumentation does not improve radiographic alignment or clinical outcomes after total knee arthroplasty.

Background and purpose - Patient-specific instrumentation (PSI) for total knee arthroplasty (TKA) has been introduced to improve alignment and reduce outliers, increase efficiency, and reduce operation time. In order to improve our understanding of the outcomes of patient-specific instrumentation, we conducted a meta-analysis. Patients and methods - We identified randomized and quasi-randomized controlled trials (RCTs) comparing patient-specific and conventional instrumentation in TKA. Weighted mean differences and risk ratios were determined for radiographic accuracy, operation time, hospital stay, blood loss, number of surgical trays required, and patient-reported outcome measures. Results - 21 RCTs involving 1,587 TKAs were included. Patient-specific instrumentation resulted in slightly more accurate hip-knee-ankle axis (0.3°), coronal femoral alignment (0.3°, femoral flexion (0.9°), tibial slope (0.7°), and femoral component rotation (0.5°). The risk ratio of a coronal plane outlier (> 3° deviation of chosen target) for the tibial component was statistically significantly increased in the PSI group (RR =1.64). No significance was found for other radiographic measures. Operation time, blood loss, and transfusion rate were similar. Hospital stay was significantly shortened, by approximately 8 h, and the number of surgical trays used decreased by 4 in the PSI group. Knee Society scores and Oxford knee scores were similar. Interpretation - Patient-specific instrumentation does not result in clinically meaningful improvement in alignment, fewer outliers, or better early patient-reported outcome measures. Efficiency is improved by reducing the number of trays used, but PSI does not reduce operation time.