Trochleoplasty Provides Good Outcomes for Recurrent Patellofemoral Dislocations with No Clear Superiority across Different Techniques.

Background: Literature is sparse on outcome comparisons between different trochleoplasty techniques in the treatment of patella instability. To date, it is unclear whether there is a technique that offers superior outcomes. This systematic review and meta-analysis aims to compare and evaluate the outcomes of trochleoplasty techniques in the treatment of patellofemoral instability in trochlea dysplasia to establish whether there is an ideal choice of trochleoplasty technique for superior outcomes. Methods: 21 studies involving 880 knees were included. The mean age of the patients was 21.7 years (range 8-49 years). Mean follow-up timeframe of 43.5 months (range 8.8-100 months). Clinical outcomes assessed included rates of recurrence of patellofemoral dislocation, patient satisfaction, Kujala score, International Knee Documentation Committee (IKDC) score, Tegner score, and Lysholm score. Egger's test showed no publication bias across all outcomes assessed. Results: Favourable results were seen across all outcomes assessed and patient satisfaction. Improvements were seen with Kujala, IKDC, and Lysholm scores. Tegner scores showed good return to function. Post-operative dislocation and complication rates were low across the different techniques. Meta-regression for Kujala and IKDC scores showed good outcomes regardless of trochleoplasty technique used (Kujala, p = 0.549, relative risk 492.06; IKDC, p = 0.193, RR 0.001). The exact risk that trochleoplasty poses to the cartilage remains uncertain, as no study had a conservatively managed arm for comparison. Conclusions: Trochleoplasty yielded good outcomes irrespective of technique used with no clear superiority demonstrated in any technique in terms of outcome scores, satisfaction, post-operative dislocation rates or complications.

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.

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.

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.

Interobserver Variability of Hip Dysplasia Indices on Sweep Ultrasound for Novices, Experts, and Artificial Intelligence.

BACKGROUND: Ultrasound for developmental dysplasia of the hip (DDH) is challenging for nonexperts to perform and interpret. Recording "sweep" images allows more complete hip assessment, suitable for automation by artificial intelligence (AI), but reliability has not been established. We assessed agreement between readers of varying experience and a commercial AI algorithm, in DDH detection from infant hip ultrasound sweeps. METHODS: We selected a full spectrum of poor-to-excellent quality images and normal to severe dysplasia, in 240 hips (120 single 2-dimensional images, 120 sweeps). For 12 readers (radiologists, sonographers, clinicians and researchers; 3 were DDH subspecialists), and a ultrasound-FDA-cleared AI software package (Medo Hip), we calculated interobserver reliability for alpha angle measurements by intraclass correlation coefficient (ICC2,1) and for DDH classification by Randolph Kappa. RESULTS: Alpha angle reliability was high for AI versus subspecialists (ICC=0.87 for sweeps, 0.90 for single images). For DDH diagnosis from sweeps, agreement was high between subspecialists (kappa=0.72), and moderate for nonsubspecialists (0.54) and AI (0.47). Agreement was higher for single images (kappa=0.80, 0.66, 0.49). AI reliability deteriorated more than human readers for the poorest-quality images. The agreement of radiologists and clinicians with the accepted standard, while still high, was significantly poorer for sweeps than 2D images (P<0.05). CONCLUSIONS: In a challenging exercise representing the wide spectrum of image quality and reader experience seen in real-world hip ultrasound, agreement on DDH diagnosis from easily obtained sweeps was only slightly lower than from single images, likely because of the additional step of selecting the best image. AI performed similarly to a nonsubspecialist human reader but was more affected by low-quality images.

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.

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.

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.

Meniscoplasty leads to good mid-term to long-term outcomes for children and adolescents with discoid lateral meniscus.

PURPOSE: To date, there have been limited studies reporting the mid- to long-term outcomes of meniscoplasties for discoid lateral meniscus. The current study aims to evaluate the mid- to long-term outcomes of arthroscopic meniscoplasty for discoid lateral meniscus in children and adolescents. METHODS: In the study, all patients under the age of 21 years who had undergone arthroscopic meniscoplasty with or without meniscal repair or partial meniscectomy for symptomatic lateral discoid meniscus were included. All patients were then followed up for a minimum of 5 years (median 84 months; range 68-110 months). The Lysholm scores and Ikeuchi scores were collected pre-operatively and at final follow-up and were compared. RESULTS: A total of 24 knees were included in the study. The median duration of follow-up was 84.0 months (range 68-110 months). The Lysholm score improved from 53 (range 11-95) pre-operatively to 100.0 (range 60-100) at final follow-up (p < 0.001). Based on the Ikeuchi score pre-operatively, 15 knees were rated as poor (62.5%), 7 knees were rated as fair (29.2%), and 2 knees were rated as good (8.4%). The Ikeuchi score improved significantly at the final follow-up, such that 1 knee was rated as good (4.2%) and 23 knees were rated as excellent (95.8%) (p < 0.001). When analysing the effect of concomitant meniscal repair or partial meniscectomy on the outcomes at final follow-up, there was no apparent difference in the improvement in Lysholm score or Ikeuchi score when comparing between patients who had meniscoplasty alone and patients who had concomitant meniscal repair, as well as when comparing between patients who had meniscoplasty alone and patients who had concomitant partial meniscectomy. CONCLUSION: Meniscoplasty leads to good mid-term to long-term outcomes for children and adolescents with discoid lateral meniscus. Concomitant procedures such as meniscal repair or partial meniscectomy do not improve or worsen the mid- to long-term outcomes in these patients. LEVEL OF EVIDENCE: IV.

The outcomes of subtalar arthroereisis in pes planus: a systemic review and meta-analysis.

INTRODUCTION: Subtalar arthroereisis has been increasingly accepted as a solution to manage symptomatic pes planus. However, despite the recent developments related to arthroereisis, no other published literature has aimed to review the outcomes in paediatric patients since 2010. This systematic review and meta-analysis, therefore, aims to evaluate the current outcomes of subtalar arthroereisis in the treatment of symptomatic pes planus among the paediatric population. MATERIALS AND METHODS: The review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All studies reported on the clinical outcomes of subtalar arthroereisis in children aged 21 or younger were included. RESULTS: A total of 17 publications were included, with 1536 feet. The average duration of follow-up of the studies included in the review is 43.52 months. The studies consistently reported improvement in the radiological outcomes, approximating that of a normal population. Subtalar arthroereisis has shown to restore the collapsed medial longitudinal arch, supported by the decrease in Meary's angle to 5.267° (95% CI: 4.695°-5.839°, normal: 0°-10.0°) post-operatively and an increased calcaneal pitch of 15.70° (95% CI: 15.41°-15.99°, normal 18.0°-20.0°). Deformities associated with pes planus such as heel valgus was also significantly reduced, evident by the post-operative lateral talocalcaneal angle of 27.19° (95% CI: 26.44°-27.93°, normal: 25.0°-45.0°) and a post-operative Kite's angle of 18.13° (95% CI: 17.73°-18.52°, normal: 15.0°-30.0°). Subjectively, subtalar arthroereisis has generally resulted in an improvement in the grading of outcomes postoperatively from the patient's point of view. CONCLUSIONS: Subtalar arthroereisis could serve as a procedure to correct radiological abnormalities, as well as relieve pain in selected patients with symptomatic pes planus.

The incidence and risk factors of osteoarthritis following osteochondritis dissecans of the knees: a systematic review and meta-analysis.

PURPOSE: The current systematic review and meta-analysis aim to pool together the incidence and risk factors of osteoarthritis following osteochondritis dissecans of the knee. METHODS: The systematic review was conducted according to PRISMA guidelines. A search was conducted using PubMed and Cochrane Library with the keywords being "knee" and "osteochondritis dissecans" or "osteochondral lesion". All original human studies that reported the incidence or risk factors of osteoarthritis following osteochondritis dissecans of the knee were included. RESULTS: Nine studies with 496 patients were included. The incidence of osteoarthritis following osteochondritis dissecans is 0.39 (95% CI 0.19-0.59). Patients with a body mass index greater than 25 kg/m2 had a significantly increased risk of osteoarthritis. Fragment excision had an increased relative risk of 1.89 (95% CI 1.19-3.01) of osteoarthritis as compared to fragment preservation. Significant heterogeneity was identified when comparing between juvenile and adult osteochondritis dissecans. The size of the lesions moderated the between-study heterogeneity with regards to the incidence of osteoarthritis, with the relative risk of osteoarthritis in lesions bigger than 4 cm2 being 2.29 (95% CI 1.24-4.23). No other risk factors, including gender of the patient, location of osteochondritis dissecans, stability of osteochondritis dissecans, and surgical versus non-surgical management were significant risk factors. CONCLUSION: Significant risk factors for osteoarthritis were increased body mass index and fragment excision. Probable but inconclusive risk factors were the age of the patients and the size of the osteochondritis dissecans. The gender of the patient, location of osteochondritis dissecans, the stability of osteochondritis dissecans, and surgical versus non-surgical management of osteochondritis dissecans when appropriate were not significant risk factors.

The Difference between Computed Tomography and Magnetic Resonance Imaging Measurements of Tibial Tubercle-Trochlear Groove Distance for Patients with or without Patellofemoral Instability: A Systematic Review and Meta-analysis.

The tibial tubercle-trochlear groove (TT-TG) distance was originally described for computed tomography (CT) but has recently been used on magnetic resonance imaging (MRI) without sufficient evidence demonstrating its validity on MRI. The current review aims to evaluate (1) whether there is a difference in the TT-TG distances measured using CT and MRI, (2) whether both the TT-TG distances measured using CT and MRI could be used to differentiate between patients with or without patellofemoral instability, and (3) whether the same threshold of 15 to 20 mm can be applied for both TT-TG distances measured using CT and MRI. The review was conducted using the preferred reporting items for systematic reviews and meta-analyses (PRSIMA) guidelines. All studies that compared TT-TG distances either (1) between CT and MRI or (2) between patients with and without patellofemoral instability were included. A total of 23 publications were included in the review. These included a total of 3,040 patients. All publications reported the TT-TG distance to be greater in patients with patellofemoral instability as compared to those without patellofemoral instability. This difference was noted for both TT-TG distances measured on CT and on MRI. All publications also reported the TT-TG distance measured on CT to be greater than that measured on MRI (mean difference [MD] = 1.79 mm; 95% confidence interval [CI]: 0.91-2.68). Pooling of the studies revealed that the mean TT-TG distance for the control group was 12.85 mm (95% CI: 11.71-14.01) while the mean TT-TG distance for patients with patellofemoral instability was 18.33 mm (95% CI: 17.04-19.62) when measured on CT. When measured on MRI, the mean TT-TG distance for the control group was 9.83 mm (95% CI: 9.11-10.54), while the mean TT-TG distance for patients with patellofemoral instability was 15.33 mm (95% CI: 14.24-16.42). Both the TTTG distances measured on CT and MRI could be used to differentiate between patients with and without patellofemoral instability. Patients with patellofemoral instability had significantly greater TT-TG distances than those without. However, the TT-TG distances measured on CT were significantly greater than that measured on MRI. Different cut-off values should, therefore, be used for TT-TG distances measured on CT and on MRI in the determination of normal versus abnormal values. Pooling of all the patients included in the review then suggest for 15.5 ± 1.5 mm to be used as the cut off for TT-TG distance measured on CT, and for 12.5 ± 2 mm to be used as the cut-off for TT-TG distance measured on MRI. The Level of evidence for this study is IV.

The Difference between Cartilaginous and Bony Sulcus Angles for Patients with or without Patellofemoral Instability: A Systematic Review and Meta-Analysis.

The cartilaginous sulcus angle and bony sulcus angle have been widely used to evaluate trochlea dysplasia. The current review aims to evaluate (1) whether there is a difference in measurement for cartilaginous and bony sulcus angles, (2) whether both the cartilaginous and bony sulcus angles could be used to differentiate between patients with or without trochlear dysplasia, and (3) whether the same cut-off of 145 degrees, originally used for radiographs, can be applied for the cartilaginous and bony sulcus angles measured on CT and MRI. The review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRSIMA) guidelines. A total of 11 publications with 1204 patients were included. All publications reported the sulcus angle to be greater in patients with patellofemoral instability. All publications reported the cartilaginous sulcus angle to be greater than the bony sulcus angle (MD 7.27 degrees; 95% CI: 5.67 - 8.87). The mean cartilaginous sulcus angle for the control group was 141.83 degrees (95% CI: 139.90 - 143.76) while the mean cartilaginous sulcus angle for patients with patellofemoral instability was 156.24 degrees (95% CI: 153.71 - 158.77). The mean bony sulcus angle for the control group was noted to be 133.69 degrees (95% CI: 131.23 - 136.15) while the mean bony sulcus angle for patients with patellofemoral instability was 148.42 (95% CI: 144.02 - 152.82). Both the cartilaginous and bony sulcus angles measured on CT and MRI could therefore be used to differentiate between patients with and without trochlear dysplasia. However, the cartilaginous sulcus angles are significantly higher than that of bony sulcus angles. Different cut off values should therefore be used.

The Outcomes of Distal Femoral Varus Osteotomy in Patellofemoral Instability: A Systematic Review and Meta-Analysis.

Distal femoral varus osteotomies have been novelly described in the recent years to be successful in the management of patellofemoral instability with genu valgum. However, these publications are limited to case reports and small case series and no published literature have attempted to analyze them in totality. The current review aims to pool together these small case series to evaluate the outcomes and complications of distal varus femoral osteotomies when performed for patellofemoral instability. The review was conducted using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. All studies that reported the outcomes of distal femoral varus osteotomy for patellofemoral instability were included. A total of five publications were included in the review, which included a total of 73 patients. All of the studies reported improvement in the radiological outcomes for genu valgum correction and patellofemoral instability. One study using opening wedge osteotomy reported a decrease in Caton-Deschamps index postoperatively, while another study using closing wedge osteotomy reported maintenance of the Caton-Deschamps index postoperatively. Second look arthroscopy showed an improvement in the status of the chondral lesions of the medial facet of the patellar undersurface, the lateral facet of the patellar undersurface and the trochlear groove 2 years postoperatively. All studies also reported a decrease in the risk of recurrence of patellofemoral instability, reduction in pain, and an improvement in all the clinical outcomes knee scores. Distal femoral varus osteotomy is promising and useful in the management of patellofemoral instability with genu valgum. The procedure can allow for radiological correction of the genu valgum and patellofemoral instability, reduction in the risk of recurrence of patellofemoral instability, reduction in pain, improvement in clinical knee outcome scores, and improvement in the status of the chondral lesions in the patellofemoral joint. It is highly versatile and could accommodate varying degrees of correction. These improvements in radiological and clinical outcomes can be seen in studies for both closing wedge and opening wedge distal femoral osteotomies. However, opening wedge osteotomies appear to decrease the patellar height as compared with closing wedge osteotomies which maintain the patellar height; therefore, the patellar height should be assessed preoperatively prior to deciding whether to perform an opening wedge or closing wedge distal femoral varus osteotomy. The Level of Evidence for this study is IV.

The Outcomes of Isolated Distal Realignment Procedures in Patellofemoral Instability: A Systematic Review and Meta-analysis.

Distal realignment procedures are now commonly performed routinely with proximal realignment procedures. Despite so, only a limited number of publications exist that have looked into the efficacy of isolated distal realignment procedures, and whether there is indeed a need for routine proximal realignment procedures to be added to the distal realignment procedures. The current systematic review and meta-analysis aims to evaluate the outcomes of isolated distal realignment procedures in the management of patellofemoral instability. The review was conducted using the preferred reporting items for systematic reviews and meta-analyses (PRSIMA) guidelines. All studies that reported the outcomes of isolated distal realignment procedures for patellofemoral instability were included. A total of six publications were included, with 347 knees. All studies consistently reported a decrease in the rates of patellofemoral instability or maltracking (odds ratio [OR]: < 0.01; 95% confidence interval [CI]: < 0.01-0.01) and an increase in the odds of having a good outcome (OR: 0.01; 95% CI: < 0.01-0.02) after distal realignment procedures. A total of 24 out of 306 patients (7.8%) had postoperative instability or maltracking, and a total of 220 out of 303 patients (72.6%) were rated to have good or excellent outcomes postoperatively. Isolated distal realignment procedures can lead to good outcomes when used in the management of patellofemoral instability. These include a significantly decreased rate of patellofemoral instability or maltracking and a significantly increased number of patients with excellent or good outcomes postoperatively. Comparisons between patients with and without additional proximal realignment procedures suggest that additional proximal realignment procedures do not definitely improve the outcomes of distal realignment procedures and, therefore, should not be routinely performed in all patients undergoing distal realignment procedures. The Level of Evidence for this study is IV.

The Outcomes of Isolated Lateral Release in Patellofemoral Instability: A Systematic Review and Meta-Analysis.

There have been conflicting reports regarding the outcomes of lateral release when used in the management of patellofemoral instability. This systematic review and meta-analysis therefore aims to evaluate the outcomes of isolated lateral release in the management of patellofemoral instability. The review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All studies that reported the outcomes of isolated lateral release for recurrent patellofemoral dislocations were included. A total of 10 publications were included, with 204 knees. All studies consistently reported a decrease in the rates of patellofemoral dislocation (odds ratio [OR] < 0.01; 95% confidence interval [CI]: <0.01-0.01) and an increase in the odds of having a good outcome (OR 0.01; 95% CI: <0.01-0.02) after lateral release. All studies also consistently reported a similar number of patients participating in sports postoperatively as compared with preinjury (OR 2.78; 95% CI: 0.53-14.68). A total of 28 (14.1%) out of 198 patients had postoperative dislocation. Of these patients, 15 required a secondary procedure for patellofemoral realignment; however, all patients who had their eventual outcomes reported still had a good outcome postoperatively. Isolated lateral release can lead to good short- to middle-term outcomes when used in the management of recurrent patellofemoral dislocations. The procedure can lead to a significantly decreased rate of recurrence of patellofemoral dislocations, a significantly increased rate of good outcomes, and a similar number of patients being able to participate in sports as compared with the number of patients participating in sports prior to having patellofemoral dislocations. An isolated lateral release could therefore potentially serve as a simple and relatively low-risk procedure that could be performed as a first-line surgical management in selected patients with patellofemoral instability, allowing them to possibly avoid a more complex and major operation. This is a Level IV study.

The earliest timing of ultrasound in screening for developmental dysplasia of the hips.

PURPOSE: The current study aimed to evaluate the results of ultrasound screening for developmental dysplasia of the hips (DDH) done at various weeks of life, to determine the earliest time that ultrasound screening can be performed reliably. METHODS: In this 17-year cohort study, all neonates who underwent ultrasound screening prior to the 12th week of life with subsequent follow-up radiography done at 1 year of life were included. The ultrasound images were evaluated according to the Graf classification, Harcke's dynamic ultrasound screening method, and Terjesen's femoral head coverage method. The radiographic images were evaluated according to the acetabular index and the femoral head position. The accuracy and correlation between the ultrasound findings from various weeks of life with the radiographic findings at 1 year of life were evaluated. RESULTS: A total of 348 neonates were included in the study, of whom 92 had abnormal ultrasound findings and 42 had abnormal radiographic findings at 1 year. Significant differences were identified between the findings of ultrasound screening examinations performed prior to the fourth week of life (day 21 and before) and the radiographic findings at 1 year of life (P<0.05). In contrast, no significant differences were identified when ultrasound screening was performed between the fourth and 12th weeks of life (day 22 and beyond) (P>0.05). The accuracy of ultrasound screening was 79.2% or higher when performed during or after the fourth week of life (day 22 and beyond). CONCLUSION: The earliest that ultrasound screening for DDH can be performed reliably is during the fourth week of life (day 22 and beyond).

Hemiepiphysiodesis is a potentially effective surgical management for skeletally immature patients with patellofemoral instability associated with isolated genu valgum.

PURPOSE: Genu valgum is one of the well-known predisposing factors for patellofemoral instability. The study aims to investigate the outcomes of isolated hemiepiphysiodesis in the correction of genu valgum and in the management of recurrent patellofemoral instability. The hypothesis was that hemiepiphysiodesis alone would result in significant correction of genu valgum, thereby preventing recurrent patellofemoral instability. METHODS: In the cohort study, all skeletally immature patients who underwent isolated hemiepiphysiodesis for recurrent patellofemoral instability were included. All patients included in the study had a minimum of 1-year follow-up duration prior to the conclusion of the study. RESULTS: Sixteen of twenty knees had no further patellofemoral instability post-operatively. The change in the status of patellofemoral instability was statistically significant (p = 0.001), similar to the change in the tibiofemoral angle (p = 0.015) and patellar tilt angle (p = 0.002). Comparison between patients with and without patellofemoral instability post-operatively revealed that the pre-operative patellar tilt angle (p = 0.005) and tibiofemoral angle (p = 0.001), post-operative patellar tilt angle (p = 0.004) and tibiofemoral angle (p = 0.027) as well as the change in patellar tilt angle (p = 0.001) and tibiofemoral angle (p = 0.001) were all significant predictors of the outcomes of genu valgum. CONCLUSION: Hemiepiphysiodesis is a potentially effective surgical management for skeletally immature patients with patellofemoral instability associated with isolated genu valgum. This is especially for patients who are skeletally immature and have sufficient remaining years for their genu valgum to be corrected using hemiepiphysiodesis. These patients also tended to have less severe genu valgum and patellar tilt angle, which could be corrected using hemiepiphysiodesis with the remaining years of growth. LEVEL OF EVIDENCE: II.