Patellar tilt, congruence angle, and tibial tubercle-trochlear groove distance are correlated with positive J-sign in adolescents.

PURPOSE: The J-sign is a clinical evaluation tool that assesses for patellar maltracking and is considered positive if lateral translation of the patella in extension, in the pattern of an inverted J is observed. This study aims to determine the association of clinical J-sign with imaging features noted on dynamic kinematic computed tomography (DKCT). METHODS: A retrospective review was conducted by reviewing the clinical records of all patients aged 18 years or younger who had a CT patellar tracking scan done between 1 January 2005 to 31 December 2016 in a single institution. Patients who had the presence or absence of a 'J-sign' evaluated clinically were included. Radiographic parameters evaluated using the axial cuts include the patellar tilt angle, congruence angle, Dejour's classification, femoral sulcus angle, trochlear groove depth, and Wiberg's classification. Patients were then divided into two groups based on the presence or absence of J-sign on clinical examination. The radiographic measurements were then analyzed for association with the presence or absence of J-sign on clinical examination. RESULTS: Patients with a positive J-sign had an increased patellar tilt of 23.3° ± 14.2° and an increased congruence angle of 47.1° ± 28.5° when measured in extension as compared to a patellar tilt of 18.3° ± 10.8° and a congruence angle of 32.1° ± 20.8° in patients with a negative J-sign (p = 0.024 and 0.004, respectively). Comparisons of the change in congruence angles with the knee in full extension and at 20° flexion also yielded significantly higher change of 28.0° ± 20.4° in patients with a positive J-sign as compared to 11.9° ± 17.5° in patients with a negative J-sign. Patients with a positive J-sign also had an increased TT-TG distance of 17.6 ± 5.6 mm as compared to a TT-TG distance of 14.7 ± 6.9 mm in patients with a negative J-sign (p = 0.01). CONCLUSION: Patients with a positive J-sign had an increased patellar tilt and an increased congruence angle when measured in extension. Increased TT-TG distance was also significantly associated with positive J-sign. Patients with a positive J-sign also had a greater change in their congruence angle when measured with the knee in full extension and at 20° of flexion.

Combination of tibial tubercle transfer, medial patellofemoral ligament reconstruction, trochleoplasty and lateral release for patellofemoral instability provides good middle- to long-term outcomes in adolescents.

PURPOSE: There are limited studies that have reported the middle- to long-term outcomes of combined procedures consisting of more than two procedures for patellofemoral instability. The current study aims to investigate and report the middle- to long-term outcomes of a combination procedure of tibial tubercle transfer, medial patellofemoral ligament reconstruction, trochleoplasty and lateral release for patellofemoral instability in patients aged 18 years and below. METHODS: In the cohort study, all patients aged 18 years old or younger who underwent a combination procedure of tibial tubercle transfer, medial patellofemoral ligament reconstruction, trochleoplasty and lateral release for recurrent patellofemoral instability were included. RESULTS: A total of 21 patients were included in the study. All patients had no further patellofemoral dislocation, pain and apprehension following the 4-in-1 surgery (p < 0.01). There was a significant improvement in the Kujala score from 36.1 (SD 12.9) pre-operatively to 93.1 (SD 3.6) post-operatively (p < 0.001). The patients also had a statistically significant improvement in their radiological factors, including the patellar tilt angle (p < 0.001), sulcus angle (p = 0.001), trochlear groove depth (p = 0.041), tibial tubercle-trochlear groove distance (p < 0.001) and Caton-Deschamps index (p = 0.001). CONCLUSION: A combination procedure of tibial tubercle transfer, medial patellofemoral ligament reconstruction, trochleoplasty and lateral release leads to good middle- to long-term subjective, functional and radiographic outcomes for patients with recurrent patellofemoral instability and underlying predisposing factors of increased TT-TG distance of more than 20 mm, Dejour B or D trochlear dysplasia and medial patellofemoral ligament rupture. LEVEL OF EVIDENCE: IV.

Risk factors for a false negative Ortolani and Barlow examination in developmental dysplasia of the hip.

INTRODUCTION: Although universal screening by neonatal clinical examination with Ortolani and Barlow manoeuvres is widely adopted, its role as a sole screening tool is controversial due to its poor sensitivity and failure in identifying hip joints that eventually require surgical intervention. HYPOTHESIS: This study aims to identify risk factors for a false negative Ortolani and Barlow examination in neonatal screening for DDH. The hypothesis is that risk factors for developmental dysplasia of the hips could similarly be risk factors for a false negative Ortolani and Barlow examination. MATERIAL AND METHODS: In the 14-year retrospective cohort study, all newborn infants born in a single institution from 1st January 1999 to 31st December 2013 were screened clinically with the Ortolani/Barlow manoeuvre by a neonatologist. Infants with positive risk factors, despite a normal clinical examination, were then scheduled for bilateral hip ultrasound in the first three months of life and evaluated according to the Graf's method, Harcke's method of dynamic ultrasound screening and Terjesen's method of evaluation for femoral head coverage. RESULTS: A total of 164 infants with normal Ortolani and Barlow examinations were scheduled for bilateral hip ultrasound due to the presence of risk factors. Amongst these, 32 (19.5%) infants were evaluated to have an abnormal hip on ultrasound. Breech position was the only statistically significant risk factor for a false negative Ortolani/Barlow examination (14/34, 41.2% vs. 18/112, 13.8%; p<0.001). DISCUSSION: Sonographic hip examinations are recommended for all infants with breech presentation even if they have a normal Ortolani and Barlow examination. LEVEL OF EVIDENCE: III; case-control study.

Histology of the volar plate of the thumb metacarpophalangeal joint.

BACKGROUND: The aim of the study was to describe the histology of the thumb MCPJ volar plate. METHODS: Five fresh-frozen thumbs were dissected. The volar plates were harvested from the thumb MCPJ. Histological analyses were performed using 0.04% Toluidine blue and counterstained with 0.005% Fast green. RESULTS: The thumb MCPJ volar plate comprised two sesamoids, dense fibrous tissue and loose connective tissue. The two sesamoids were connected by dense fibrous tissue, with collagen fibers oriented transversely (perpendicular to the long axis of the thumb). In contrast, the collagen fibers within the dense fibrous tissue on the lateral sides of the sesamoid were oriented longitudinally in line with long axis of the thumb. These fibers blended with the fibers of the radial and ulnar collateral ligaments. The collagen fibers in the dense fibrous tissue distal to the sesamoids ran transversely, perpendicular to the long axis of the thumb. The proximal aspect of the volar plate showed only loose connective tissue. The volar plate of the thumb MCPJ was largely uniform with no division of layers from the dorsum to the palmar surface. There was no fibrocartilaginous component in the thumb MCPJ volar plate. CONCLUSIONS: The histology of the volar plate of the thumb MCPJ differs significantly from the conventional understanding of the volar plate, based on the volar plate of finger proximal interphalangeal joints. The difference is likely due to the presence of the sesamoids, which confer additional stability, reducing the need for a specialized trilaminar fibrocartilaginous structure with the lateral check-rein ligaments found in the volar plate of finger proximal interphalangeal joints to confer additional stability.

Morbidities and prognostic factors after tibial pilon fracture: impact on patients.

INTRODUCTION: This study aims primarily to characterize the sequelae and morbidity associated with tibial pilon injuries from the patients' perspectives in terms of multiple surgical interventions, duration of hospital stay, downtime from work, loss of productivity and impact on patients' lives. The secondary aim is to review the associated risk factors for these morbidities. MATERIALS AND METHODS: All patients with surgically treated tibial pilon fractures from 1st July 2007 to 30th June 2017 were included. The morbidities reviewed focused on delay to surgery, numbers of surgeries, limb amputation, length of stay (LOS), readmissions, duration of medical leave (ML), follow-up and number of outpatient visits. RESULTS: There were 102 patients included in the review and up to 70% of them had an average 7 days delay to definitive surgery. They also required an average hospital LOS of at least 2 weeks extending up to 3 more weeks if soft tissue reconstruction was necessitated. Up to a third of patients were readmitted with 15% of them needing further treatment. These patients required a notable period of downtime from work as shown in the long ML (mean 152.6 days [S.D. = 110.7]). Multiple conditional regression models showed AO/OTA classification (B and C) and open fracture as independent predictors of delay to surgery. Predictors for increased LOS were high velocity mechanism of injury at 4 days longer and patients who needed soft tissue reconstruction at 21 days longer. In terms of downtime from work, only work injury has been identified as an independent predictor of ML at 88.5 days longer. CONCLUSION: Tibial pilon fractures leads to significant morbidities with profound negative impact on patients' lives in terms of multiple surgical interventions required, prolonged hospital stay, need for readmissions and prolonged downtime from work. These morbidities from patients' perspective should be emphasized to patients and employers to manage their expectations and potential limitations.

Epidemiology and estimated economic impact of musculoskeletal injuries in polytrauma patients in a level one trauma centre in Singapore.

Introduction: Musculoskeletal injuries are the most common reason for surgical intervention in polytrauma patients. Methods: This is a retrospective cohort study of 560 polytrauma patients (injury severity score [ISS] >17) who suffered musculoskeletal injuries (ISS >2) from 2011 to 2015 in National University Hospital, Singapore. Results: 560 patients (444 [79.3%] male and 116 [20.7%] female) were identified. The mean age was 44 (range 3-90) years, with 45.4% aged 21-40 years. 39.3% of the patients were foreign migrant workers. Motorcyclists were involved in 63% of road traffic accidents. The mean length of hospital stay was 18.8 (range 0-273) days and the mean duration of intensive care unit (ICU) stay was 5.7 (range 0-253) days. Patient mortality rate was 19.8%. A Glasgow Coma Scale (GCS) score <12 and need for blood transfusion were predictive of patient mortality (p < 0.05); lower limb injuries, road traffic accidents, GCS score <8 and need for transfusion were predictive of extended hospital stay (p < 0.05); and reduced GCS score, need for blood transfusion and upper limb musculoskeletal injuries were predictive of extended ICU stay. Inpatient costs were significantly higher for foreign workers and greatly exceeded the minimum insurance coverage currently required. Conclusion: Musculoskeletal injuries in polytrauma remain a significant cause of morbidity and mortality, and occur predominantly in economically productive male patients injured in road traffic accidents and falls from height. Increasing insurance coverage for foreign workers in high-risk jobs should be evaluated.

Both Medialization and Anteromedialization Tibial Tubercle Osteotomies are Effective Surgical Management for Skeletally Mature Patients with Patellofemoral Instability when Combined with Medial Patellofemoral Ligament Reconstruction.

The study aimed to compare the midterm outcomes of medialization and anteromedialization tibial tubercle osteotomies when used in the management of recurrent patellofemoral instability. The hypothesis is that both techniques would result in significant improvement for patellofemoral instability, but anteromedialization would result in a lower incidence of early osteoarthritis. In the cohort study, all skeletally mature patients aged 18 years old or younger who underwent tibial tubercle osteotomy for recurrent patellofemoral instability within a 10-year period in a single institution were included. All patients underwent either medialization or anteromedialization tibial tubercle osteotomy. The preoperative and postoperative outcomes of the tibial tubercle osteotomies were compared. All patients included in the study had a minimum of 5-year follow-up duration before the conclusion of the study. There was no statistically significant difference in the rates of preoperative and postoperative patellofemoral dislocation when either technique was employed (p = 0.999). Additionally, both the preoperative and postoperative Kujala scores were similar (p = 0.166 and p = 0.554, respectively). The knees did not have a statistically significant difference in their patellar tilt angles and tibial tubercle-trochlear groove distances preoperatively or postoperatively when either technique was used (p = 0.165 and 0.149, respectively). There was also no incidence of osteoarthritis identified in either of the groups (p = 0.999). Both anteriorization and anteromedialization tibial tubercle osteotomies were effective surgical management for patellofemoral instability when combined with medial patellofemoral ligament reconstruction. There were no significant differences in clinical, functional, and radiological outcomes when either medialization or anteromedialization tibial tubercle osteotomy was performed.

Predictive Scoring for Recurrent Patellar Instability After a First-time Patellar Dislocation.

PURPOSE: Patellofemoral instability is a common acute knee injury seen in the pediatric population. First-time patellar dislocations usually undergo conservative management, but ~15% to 80% of patients experience recurrent instability. This study aims to develop a prediction model using radiographic parameters of the patellofemoral joint seen on computed tomography scans in different degrees of knee flexion, to determine the risk of recurrence after the first episode of patellofemoral instability. METHODS: A 12-year retrospective case-control study was performed. All patients in a single institution aged 18 years or younger who had a computed tomography patellar tracking scan performed for patellar instability were included. Predictors included in the score were determined through backward logistic regression and compared using receiver operating characteristic curve analysis. RESULTS: This study revealed that recurrent dislocation in first-time patellofemoral dislocation could be accurately predicted using the prediction score that consisted of age, tibial tubercle-trochlear groove distance and congruence angle at 10- and 20-degree flexion. The sensitivity of the score was 100% and specificity was 73.3%. Three diagnostic zones were identified and used to categorize patients into low-, intermediate-, and high-probability groups. CONCLUSION: This study presented a scoring system that incorporated radiographic knee kinematics in the risk assessment for recurrent patellofemoral instability for patient stratification. The scoring system could guide the decision for early surgical intervention after the first-episode patellofemoral dislocation for patients at high risk of recurrent patellofemoral dislocation.

Hip survivorship following the Bernese periacetabular osteotomy for the treatment of acetabular dysplasia: A systematic review and meta-analysis.

INTRODUCTION: The Bernese periacetabular osteotomy (PAO) is a popular joint-preservation technique aimed at addressing the structural and biomechanical abnormalities associated with acetabular dysplasia. However, the prognostic factors and long-term survivorship of the native hip, with failure defined as conversion to total hip arthroplasty (THA), is poorly understood. Our study aims to address the following: (1) What is the estimated duration of survival of the native hip post-PAO, (2) What are some prognostic factors of functional outcome and (3) What is the complication rate and complications associated with PAO. HYPOTHESIS: The Bernese PAO is able to result in favourable mid- to long-term outcomes conditional on a stringent patient selection criteria. MATERIALS AND METHODS: A systematic review was performed using the PRISMA guidelines. All studies that reported on the outcomes of isolated Bernese PAO for the treatment of acetabular dysplasia were included. RESULTS: A total of 24 studies (3471 patients, 3655 hips) were included at a mean follow-up duration of 54.2months (range: 1-336months). In total, 208 hips (6.03%; 95% CI: 5.25-6.94%) converted to THA at a mean duration of 4.71years (range: 1-240months). Univariate analysis identified advanced age beyond a follow-up duration of 6years (p=0.001) and preoperative Tönnis grade 2 and above (p<0.001) to be the most significant negative prognostic factors. Beyond a follow-up duration of 2years, intraoperative fluoroscopy proved to be a significant positive prognostic factor (p<0.001). Indications for PAO, obesity and gender were not found to be significant predictors of failure. Our study found the complication rate to be 23.5% (95% CI: 21.6-25.6%). The most common complications detailed are transient lateral femoral cutaneous nerve dysesthesia (8.24%; 95% CI: 7.02-9.65%), stress fracture (5.28%; 95% CI: 4.31-6.89%) and the delayed union, non-union or pseudoarthrosis of the ramus not necessitating surgical correction (3.73%, 95% CI: 2.93-4.75%). DISCUSSION: PAO alters the natural history of the dysplastic hip with a 10- and 20-year survivorship of approximately 75.9% and 36.5% of patients respectively. The ideal patient should be below 40years old, with a preoperative Tönnis grade of 0 or 1. Intraoperative fluoroscopy is able to guide a better precision when re-orientating the acetabulum. LEVEL OF EVIDENCE: IV; systematic review and meta-analysis.

Should the location of distal tibial plating be influenced by the varus or valgus fracture pattern of tibial pilon fracture?

INTRODUCTION: Operative treatment of tibial pilon fracture is challenging. There is a lack of consensus and only one clinical study on the optimal location of distal tibial plating for fixation of pilon fractures based on varus or valgus fracture patterns. We hypothesize that complications rates, specifically mechanical complications, are not influenced by the location of the tibial plating in the fixation of pilon fractures with respect to varus or valgus fracture patterns. MATERIALS AND METHODS: Sixty-nine patients who had single plating for tibial pilon from 2007 to 2017 were recruited. They were divided into two groups, transverse fibular fracture (varus fracture pattern) and comminuted fibular fracture (valgus fracture pattern). Our primary outcome measure was any mechanical complications as a result of the location of plating (medial vs lateral) on varus or valgus fracture patterns. RESULTS: There were 38 (55.1%) patients with varus fracture pattern and 31 (44.9%) patients with valgus fracture pattern tibial pilon fractures. In the varus fracture pattern group, mechanical complications were not significantly different between the two plating locations (27.3 vs 33.3%, p > 0.05). Notably, there were more fibula fixations performed in patients with medial plating (74.1 vs 45.5%, p = 0.092) when compared those with lateral plating in the varus fracture pattern group. There were also no statistically significant differences found although 10 (40%) out of 25 patients had mechanical complications in the medial plating group compared to 1 (16.7%) out of 6 patients with lateral plating (p = 0.383) in the valgus fracture pattern group. CONCLUSION: There were no differences in mechanical complications for medial vs lateral plating in tibial pilon fracture based on varus or valgus deforming forces. As much as we should consider the fracture patterns and deforming forces when deciding on plating location, other factors such as careful soft tissue management and fragment-specific fixation should be prioritized.

Accuracy of biplanar linear radiography versus conventional radiographs when used for lower limb and implant measurements.

INTRODUCTION: The current standard of care for measuring lower extremity length and angular discrepancies is using a full-length standing anteroposterior radiograph. However, there has been increasing interest to use biplanar linear EOS imaging as an alternative. This study aims to compare lower extremity length and implant measurements between biplanar linear and conventional radiographs. MATERIALS AND METHODS: In this 5-year retrospective study, all patients who had a standing full-length anteroposterior and biplanar linear radiographs (EOS®) that include the lower extremities done within one year of each other were included. Patients who underwent surgery in between the imaging, underwent surgeries that could result in graduated length or angulated corrections and inadequate exposure of the lower extremity were excluded. Four radiographic segments were measured to assess lower limb alignment and length measurements. Height and width measurements of implants were performed for patients who had implants in both imaging. RESULTS: When comparing imaging and actual implant dimensions, biplanar linear radiographs were accurate in measuring actual implant height (median difference = - 0.14 cm, p = 0.66), and width (median difference = - 0.13 cm, p = 0.71). However, conventional radiographs were inaccurate in measuring actual implant height (median difference = 0.19 cm, p = 0.01) and width (median difference = 0.61 cm, p < 0.01). When comparing conventional and biplanar linear radiographs, there was statistically significant difference in all measurements. This includes anatomical femoral length (median difference = 3.53 cm, p < 0.01), mechanical femoral length (median difference = 3.89 cm, p < 0.01), anatomical tibial length (median difference = 2.34 cm, p < 0.01) and mechanical tibial length (median difference = 2.20 cm, p < 0.01). CONCLUSION: First, there is a significant difference in the lower extremity length when comparing conventional and biplanar linear radiographs. Second, biplanar linear radiographs are found to be accurate while conventional radiographs are not as accurate in implant measurements of length and width in the lower extremity.

Surgical outcomes in paediatric lateral condyle non-union: A systematic review and meta-analysis.

AIMS: Non-union is a known and much-dreaded complication of paediatric lateral condyle fractures. This systematic review aims to pool together individual studies to find out if the timing of fixation and method of fixation impacts surgical outcomes (postoperative union and elbow ROM) in paediatric lateral condyle non-union. METHODS: A systematic review and individual patient data meta-analysis was conducted according to PRISMA guidelines. All surgical studies with original data on pediatric lateral humeral condyle non-union were included. Patients who did not undergo surgical fixation were excluded. RESULTS: A total of 12 studies with 177 patients were included. In total, 159 patients (89.8%) achieved bony union postoperatively while 18 patients (10.2%) did not. Mixed-effects logistic regression showed that percutaneous fixation (p-value=0.020) was associated with lower rates of postoperative union compared to open fixation, whereas the age at surgery did not have a significant impact (p-value=0.401). For elbow ROM, mixed-effects linear regression showed that increased age at surgery (p-value=0.007) and reduction of the fracture fragment (vs. in situ fixation) (p-value=0.041) were associated with reduced postoperative ROM whereas female sex (p-value=0.009) and corrective osteotomy (p-value=0.045) were associated with increased postoperative ROM. CONCLUSION: While the timing of surgical fixation did not significantly impact postoperative bony union, undergoing fixation at an older age was associated with reduced postoperative elbow ROM. In addition, percutaneous fixation may be associated with poorer postoperative union compared to open fixation while anatomical reduction may be associated with reduced postoperative elbow ROM compared to in situ fixation. LEVEL OF EVIDENCE: IV.

Surgical Management of Missed Pediatric Monteggia Fractures: A Systematic Review and Meta-Analysis.

OBJECTIVES: To review surgical management and outcomes of missed pediatric Monteggia fractures. DATA SOURCES: A systematic review was conducted using PubMed, Medical Literature Analysis and Retrieval System Online (MEDLINE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), and the Cochrane Library from inception through March 2, 2020. The keywords were "Monteggia fracture," "missed Monteggia," "neglected Monteggia," "chronic Monteggia," and "chronic radial head dislocation." STUDY SELECTION: All original human studies on missed pediatric Monteggia fractures were included. Congenital Monteggia fractures and isolated radial head dislocations were excluded. DATA EXTRACTION: The revised Methodological Index for Nonrandomised Studies tool was used to assess the quality of studies. DATA SYNTHESIS: Each patient's data were retrieved individually. The χ2 test and Fisher exact test were used to analyze the difference in outcomes for different surgical managements. Multivariate analysis was performed for variables that were significant on univariate analysis. CONCLUSIONS: Thirty studies with 600 patients were included. Proximal ulnar osteotomies (P = 0.016) and the absence of transcapitellar pinning (P = 0.001) were the most significant predictors for eventual reduction of radial head. Other surgical management variables were not significant predictors. These include open or closed reduction approach of radial head reduction; presence or absence of ulnar osteotomy; presence or absence of lengthening, angular correction, overcorrection, or bone grafting of ulnar osteotomy; type of fixation for ulnar osteotomy; presence or absence of radial osteotomy; presence or absence of annular ligament repair or reconstruction; and repair or reconstruction of annular ligament. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Fibula fixation in the treatment of tibial pilon fractures - Is it really necessary?

BACKGROUND: There is a lack of consensus about the role of fibula fixation in these complex fractures, with only two clinical studies in the literature. We hypothesize that the fibula fracture need not be fixed in the tibial pilon fractures if primary stability can be achieved with tibial fixation alone. METHODS: We reviewed 79 patients with operatively treated tibial pilon with associated fibula fractures from 2007 to 2017 and divided them into two groups; patients with fibula fracture fixation and those without fixation. The primary outcome measure was any mechanical complications. Secondary outcomes were wound complications and other morbidities. RESULTS: There were 54 (68.4%) patients with fibula fixation and 25 (31.6%) patients without fixation. There were no statistically significant differences in mechanical complications between the two groups. However, patients without fibula fixation were noted to have more wound complications (44% vs 25.9%, p = 0.108) although this was not statistically significant. In terms of removal of implant (ROI), there were no differences noted in patients with or without fibula fixation (33.3% vs 28%, p = 0.796). There were also no significant differences in ROI for those fixed with plate and screws when compared to those fixed with Rush rod and K wire within the group with fibula fixation. CONCLUSION: Fibula fixation in the treatment of tibial pilon fractures is not routinely necessary and does not result in decreased mechanical complications such as malunion, delayed union, nonunion and implant failure. Fibula fracture fixation should be reserved for cases where it may aid reduction or provide additional stability.

Osteochondral tissue engineering: Perspectives for clinical application and preclinical development.

The treatment of osteochondral defects (OCD) remains challenging. Among currently available surgical treatments for OCDs, scaffold-based treatments are promising to regenerate the osteochondral unit. However, there is still no consensus regarding the clinical effectiveness of these scaffold-based therapies for OCDs. Previous reviews have described the gradient physiological characteristics of osteochondral tissue and gradient scaffold design for OCD, tissue engineering strategies, biomaterials, and fabrication technologies. However, the discussion on bridging the gap between the clinical need and preclinical research is still limited, on which we focus in the present review, providing an insight into what is currently lacking in tissue engineering methods that failed to yield satisfactory outcomes, and what is needed to further improve these techniques. Currently available surgical treatments for OCDs are firstly summarized, followed by a comprehensive review on experimental animal studies in recent 5 years on osteochondral tissue engineering. The review will then conclude with what is currently lacking in these animal studies and the recommendations that would help enlighten the community in developing more clinically relevant implants. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: This review is attempting to summarize the lessons from clinical and preclinical failures, providing an insight into what is currently lacking in TE methods that failed to yield satisfactory outcomes, and what is needed to further improve these implants.

Periacetabular osteotomy for acetabular retroversion: A systematic review and meta-analysis.

INTRODUCTION: The evidence for periacetabular osteotomy (PAO) when used in the management of acetabular retroversion remain limited. The review aims to answer the following questions: (1) What are the indications for an anteverting PAO for acetabular retroversion? (2) When are other concomitant procedures required when performing anteverting PAO for acetabular retroversion? (3) To what extent is an anteverting PAO able to correct acetabular retroversion? (4) What are the clinical outcomes for an anteverting PAO when used in acetabular retroversion? (5) What is the estimated survival for anteverting PAO when used in the treatment of acetabular retroversion, before other procedures need to be performed? (6) What are the complications and the complication rates when an anteverting PAO is performed? (7) How do the outcomes of an anteverting PAO compare to other surgical procedures used in the management of acetabular retroversion? MATERIAL AND METHODS: The systematic review was conducted using the PRISMA guidelines. The search was conducted using PubMed Medical Literature Analysis and Retrieval System Online (MEDLINE) and Cumulative Index to Nursing and Allied Health Literature (CINAHL) from inception through 1 May 2020. The keywords used were "periacetabular osteotomy". All studies that reported the outcomes of periacetabular osteotomy for acetabular retroversion were included. Each study's data was then retrieved individually. The study design, surgical technique, indications, outcomes and complications of each study were analysed. RESULTS: Seven studies with 225 hips were included. The pooled odds ratio (OR) for a positive crossover sign and posterior wall sign preoperatively as compared to postoperatively were 456.31 (95% CI: 99.57 to 2091.28) and 53.45 (95% CI: 23.05 to 123.93) respectively. The pooled weighted mean difference (WMD) for studies with their mean preoperative LCEA and AI in the dysplastic range were 12.61 (95% CI: 6.54 to 18.68) and-15.0 (95% CI: -19.40 to -11.80) respectively, while the pooled WMD for studies with their mean preoperative LCEA and AI in the normal range were 3.43 (95% CI: 1.08 to 5.77) and -3.56 (95% CI: -5.29 to -1.83) respectively. Other indicators for acetabular retroversion correction, hip dysplasia correction, functional outcomes and range of motion were also significantly improved and sustained up till 11 years postoperatively. Only 7.1% of the hips required subsequent surgical procedures for impingement symptoms or progression of osteoarthritis, and the mean estimate for survival time across the studies was 123.90 months (95% CI: 119.94 to 127.86). The complication rates for low-grade complication were 31.6% while the rate for high-grade complications was 12.0%. DISCUSSION: Anteverting PAO is indicated for symptomatic acetabular retroversion, and when performed, leads to good deformity correction for both acetabular retroversion and hip dysplasia, positive improvement in clinical outcomes sustainable till 11 years postoperatively and a mean estimated survival time of more than 10 years. LEVEL OF EVIDENCE: IV; Systematic review and meta-analysis.

Outcomes of High Tibial Osteotomy With Versus Without Mesenchymal Stem Cell Augmentation: A Systematic Review and Meta-analysis.

BACKGROUND: The outcomes after high tibial osteotomy (HTO) with augmentation of intra-articular mesenchymal stem cell (MSCs) for medial tibiofemoral osteoarthritis remain controversial. PURPOSE: To pool existing studies to compare the outcomes of HTO with versus without intra-articular MSC augmentation when performed for medial tibiofemoral osteoarthritis. STUDY DESIGN: Systematic review; Level of evidence, 3. METHODS: The systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Included were clinical studies that compared the outcomes of HTO with intra-articular MSC augmentation (MSC group) versus without (control group). Pre- and postoperative outcomes were compared between groups from measures including the Lysholm score, International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score, Hospital for Special Surgery Knee Rating Scale, Tegner score, visual analog scale for pain, arthroscopic and histological grading scales, femorotibial angle, weightbearing line, and posterior tibial slope. RESULTS: We reviewed 4 studies with a total of 224 patients. The MSC group demonstrated significantly greater improvement versus controls in the pooled Lysholm score (weighted mean difference [WMD], 6.64; 95% CI, 0.90 to 12.39) and pooled IKDC score (WMD, 9.21; 95% CI, 4.06 to 14.36), which were within or close to the minimal clinically important difference. Radiological outcomes were similar in both groups, including the femorotibial angle (WMD, -0.01; 95% CI, -1.10 to 1.09), weightbearing line, and posterior tibial slope. The studies were homogeneous, and no publication bias was noted. CONCLUSION: Intra-articular MSC augmentation for HTO may modestly improve functional outcomes as compared with HTO alone. However, adequate data are lacking to make definitive conclusions regarding the effect of MSC augmentation on pain or arthroscopic and histologic grading.

Surgical Management of Patella Alta in Patellofemoral Instability: A Systematic Review and Meta-analysis.

BACKGROUND: Proximal, distal, and combined proximal and distal procedures have been performed for patellofemoral instability in the presence of patella alta. No consensus exists regarding the accepted surgical management for this condition. PURPOSE: To pool the outcomes of surgical management for patellofemoral instability in the presence of patella alta and to determine whether the outcomes differ for different surgical techniques. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: This systematic review was conducted using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. All studies that reported surgical outcomes for patellofemoral instability in the presence of patella alta were included. The random-effects model was used to analyze pooled estimates of preoperative and postoperative differences for outcomes that were reported in ≥3 studies. If heterogeneity existed among the studies, further analysis was performed using random-effects meta-regression analysis, which allowed for the identification of moderators. RESULTS: A total of 11 studies with 546 knees were included. The pooled relative risk (RR) of having no patellofemoral dislocation and no patellofemoral apprehension or subjective instability postoperatively was 51.80 (95% CI, 20.75-129.31) and 48.70 (95% CI, 17.22-137.71), respectively. The pooled weighted mean improvement (WMI) for the Kujala and Lysholm scores postoperatively was 31.98 (95% CI, 28.66-35.30) and 35.93 (95% CI, 30.12-41.74), respectively. The pooled WMI for patellar tilt angles postoperatively was 10.94 (95% CI, 7.87-14.01). These outcomes were homogeneous across all studies. The pooled WMI for Insall-Salvati ratio, Caton-Deschamps index, and tibial tubercle-trochlear groove distance postoperatively was 0.31 (95% CI, 0.17-0.45), 0.24 (95% CI, 0.12-0.36), and 6.77 (95% CI, 1.96-11.58), respectively. These outcomes were heterogeneous across the studies, with the presence of distal procedures being a significant moderator. The presence of distal procedures had a significantly higher unweighted RR of 38.07 (95% CI, 2.37-613.09) for major complications compared with proximal procedures alone, although the incidence of minor complications was comparable (unweighted RR, 1.25; 95% CI, 0.35-4.48). CONCLUSION: Surgical management for patellofemoral instability in the presence of patella alta consistently led to improvement in clinical and functional outcomes, regardless of the type of procedure performed. Distal procedures were better able to correct the patellar height and tibial tubercle-trochlear groove distance, although these procedures also posed a higher RR of subsequent surgery compared with proximal procedures alone.