[Patellofemoral instability in children and adolescents]. / Patellofemorale Instabilität bei Kindern und Jugendlichen.

Patellofemoral instability is a common and clinically relevant disorder of multifactorial causes. Several concomitant problems such as genua valga, hyperlaxity, injuries or sports-related overuse may contribute to the development of instability and recurrent patellar dislocations. A thorough diagnosis is of paramount importance to delineate every contributing factor. This includes radiographic modalities and advanced imaging such as magnetic resonance imaging or torsional analyses. The authors recommend non-operative management (including physiotherapy, gait and proprioceptive training, orthoses) and, whenever non-operative measures fail, surgical patellar stabilization using, e.g. MPFL reconstruction.

[Osteochondral fractures in childhood and adolescence]. / Osteochondrale Frakturen im Kindes- und Jugendalter.

BACKGROUND: Osteochondral fractures (OCF) are traumatic shearing injuries to portions of cartilage and bone. The most common cause is patellar dislocation, with the main localisation being the medial patellar facet and the lateral femoral condyle. They can occur in all age groups. DIAGNOSIS: Clinically, there is a painful knee joint effusion (haemarthrosis) with a "dancing patella". This is usually accompanied by restricted movement and/or a locking phenomenon. In addition to the standard X­ray of the knee in three planes (lateral, anterior-posterior and tangential patella), an MRI should be performed promptly in the case of haemarthrosis and suspicious symptoms, as concomitant injuries are present in up to 70% of cases. TREATMENT: The aim of treatment is to restore joint congruence in order to prevent the risk of secondary osteoarthritis. Small chondral and stable osteochondral fractures can be treated conservatively. Surgery is indicated for all other OCFs. In addition to refixation with various materials (bioresorbable screws, bone plugs, suture material and Kirschner wires), cartilage regeneration procedures (AMIC, MACI, OAT, etc.) are available for late diagnosed or non-refixable fragments. However, the number of cases is small. CONCLUSION: Osteochondral fractures are rare injuries in children and adolescents. Prompt MRI is recommended for diagnosis in cases of suspected OCF. Refixation is the preferred treatment method, with bioresorbable implants showing promising results in reducing the need for additional surgery. The risk of secondary osteoarthritis can be reduced with regular treatment.

Minimal effect of scanning parameters on ultrasound shear wave elastography variability in tendons.

PURPOSE: Ultrasound shear wave elastography has potential use in assessing tendon tissue; however, reducing measurement variability remains challenging. The primary purpose of this study was to identify the amount of variability accounted for by ultrasound parameter (frequency, harmonics and CrossXBeam) settings on shear wave speed at two testing sites. METHODS: Shear wave elastography images of the Achilles tendon were obtained from individuals with healthy tendons (n = 28) at two testing sites with standardised image acquisition/postprocessing protocols. Images were acquired at a range of frequencies (7-15 MHz) with CrossXBeam (a filtering technique) and harmonics settings toggled on and off. Variance decomposition analysis was performed to identify the amount of variability in shear wave speed accounted for by scan acquisition settings and testing sites. RESULTS: Shear wave speed variance was primarily attributed to participants (56.87% of variance; residual error: 35%). All scanning parameters, testing site and interaction terms each accounted for less than 2.5% of the variance. A statistically significant, negative relationship was observed between shear wave speed and image quality (p = 0.001) suggesting poor image quality yields higher shear wave speed estimates. CONCLUSION: The findings of this study suggest that natural variation in Achilles tendon mechanics between individuals without tendon pathology accounts for most of the shear wave speed variability. Optimising image quality, which may be observed in higher frequencies, should be considered to improve shear wave speed estimation. Clinically, this study highlights the need to take multiple images, maintain consistent ultrasound settings when tracking patient progress over time and use caution when comparing raw values from tendon scans performed in different clinics with shear wave elastography. LEVEL OF EVIDENCE: Level III.

Preoperative subjective assessment of disease-specific quality of life significantly influenced the likelihood of achieving the minimal clinically important difference after surgical stabilization for recurrent lateral patellar instability.

PURPOSE: To evaluate which factors exert a predictive value for not reaching the minimal clinically important difference (MCID) in patients who underwent a tailored operative treatment for recurrent lateral patellar dislocation (RLPD). METHODS: A total of 237 patients (male/female 71/166; 22.4 ± 6.8 years) were included. The Banff Patellofemoral Instability Instrument 2.0 (BPII 2.0) and subjective rating of knee function and pain (numeric analogue scale [NAS]; 0-10) were used to evaluate patients' outcomes from pre- to postoperatively. Gender, age at the time of surgery, body mass index (BMI), nicotine abuse, psychiatric diseases, cartilage status and pathoanatomic risk factors were evaluated as potential predictors for achieving the MCID using univariate logistic regression analysis. RESULTS: The MCID for the BPII 2.0 was calculated at 9.5 points. Although the BPII 2.0 and NAS for knee function and pain improved significantly in the total cohort from pre- to postoperatively (all p < 0.001), 29 patients did not reach the MCID at the final follow-up. The analysis yielded that only the preoperative NAS for function and BPII 2.0 score values were significant predictors for reaching the MCID postoperatively. The optimal threshold was calculated at 7 (NAS function) and 65.2 points (BPII 2.0). Age at the time of surgery should be considered for patients with a preoperative BPII 2.0 score >62.5. CONCLUSION: The probability of reaching BPII 2.0 MCID postoperatively depends only on the preoperative BPII 2.0 value and subjective rating of knee function, as well as age at the time of surgery for patients undergoing surgical treatment of RLPD. Here, presented results can assist clinicians in advising and presenting patients with potential outcomes following treatment for this often complex and multifactorial pathology. LEVEL OF EVIDENCE: Level III.

Application of a machine learning and optimization method to predict patellofemoral instability risk factors in children and adolescents.

PURPOSE: Conservative treatment remains the standard approach for first-time patellar dislocations. While risk factors for patellofemoral instability, a common paediatric injury, are well-established in adults, data concerning the progression of paediatric recurrent patellar dislocation remain scarce. A reproducible method was developed to quantitatively assess the patellofemoral morphology and anatomic risk factors in paediatric patients using magnetic resonance imaging (MRI) and machine learning analysis. METHODS: Data were analyzed from a retrospective review (2005-2022) of paediatric patients diagnosed with acute lateral patellar dislocation (54 patients) who underwent MRI and were compared with an age-based control group (54 patients). Patellofemoral, tibial, tibiofemoral and patellar height parameters were measured. Differences between groups were analyzed with respect to MRI parameters. The potential diagnostic utility of the parameters was assessed via machine learning and genetic algorithm analyses. RESULTS: Significant differences were observed between the two groups in six patellofemoral morphological parameters. Regarding patellar height morphological parameters, all methods exhibited significant between-group differences. Among the tibia and tibiofemoral morphological parameters, only the tibial tubercle-trochlear groove distance exhibited significant differences between the two groups. No sex-related differences were present. Significant variations were observed in patellar height parameters, particularly in the Koshino-Sugimoto (KS) index, which had the highest area under the curve (AUC: 0.87). Using genetic algorithms and logistic regression, our model excelled with seven key independent variables. CONCLUSION: KS index and Wiberg index had the strongest association with lateral patellar dislocation. An optimized logistic regression model achieved an AUC of 0.934. Such performance is considered clinically relevant, indicating the model's effectiveness for the intended application. LEVEL OF EVIDENCE: Level Ⅲ.

Combined Hip and Knee Strengthening Compared With Knee Strengthening for Individuals With Lateral Patellar Dislocation: A Single-blind, Superiority, Randomized Controlled Trial.

Objective: To investigate whether a combined hip and knee muscle strengthening program is superior to a knee strengthening program for people after lateral patellar dislocation (LPD). Design: Single-blind, superiority, randomized controlled trial with 48 weeks follow-up. Setting: Physiotherapy out-patient clinic. Participants: Forty individuals aged 16 or older, with a history of non-traumatic LPD were randomized to a knee-based strengthening (KBSG) or quadriceps and hip strengthening exercise (HQSG) program (N=40). Inclusion criteria included a positive apprehension sign, pain on palpation along the medial retinaculum, and J sign. Exclusion criteria included restricted range of motion (<90° knee flexion), and traumatic or postsurgical LPD. Interventions: Concealed randomization was performed using random permuted blocks of size 4. Individuals received their corresponding exercise program according to randomization and group allocation: knee-based strengthening (n=20) or combined hip and quadriceps strengthening (n=20) twice weekly for 8 weeks over 16 appointments. Main Outcome Measures: Primary outcome was the Lysholm Knee Score. Secondary outcomes included Numerical Pain Ratings Scale (NPRS) at rest and during effort, Norwich Patellar Instability Score (NPIS), Kujala Anterior Knee Pain Scale (AKPS), Lower Extremity Functional Scale (LEFS), 4 domains of the WHOQOL-Bref, and recurrence rate. Patient-reported outcome measures were assessed from the baseline to 48 weeks. Assessments were performed by a physiotherapist who was blinded to the group allocation. Data were analyzed by using a repeated-measures ANOVA model with Tukey's post hoc test after an intention-to-treat principle. Results: At the primary time-point of 8 weeks, there were no substantial between-group differences in the Lysholm Knee Score: mean difference=-6.8 (95% CI -14.3 to 3.7); NPIS: mean difference=23.5 (95% CI 5.6 to 41.3); AKPS: mean difference=-1.54 (95% CI -8.6 to 5.6), NPRS at rest and during effort (mean difference=0.32 (95% CI -0.37 to 1); and mean difference=0.68 (95% CI -0.9 to 1.86); LEFS mean difference=-1.08 (95% CI -5.9 to 2.4), WHOQOL-Bref domains (physical health: mean difference=-0.12, (95% CI -1.26 to 1.02); psychological: mean difference=-0.32 (95% CI -2.04 to 1.4); social relations: mean difference=-0.7 (95% CI -2.2 to 0.82); environment: mean difference=0.44 (95% CI -1 to 1.9), and recurrence rate (P=.69). Conclusion: This study indicates that combined hip and knee muscle strengthening is not superior to knee-based strengthening for LPD treatment. The limitations stemming from the underpowered nature of the trial must be acknowledged, concerning the potential oversight of moderate intervention effects.

Assessing the Effectiveness of Modified Tibial Plateau Leveling Osteotomy Plates for Treating Cranial Cruciate Ligament Rupture and Medial Patellar Luxation in Small-Breed Dogs.

In small-breed dogs with concurrent cranial cruciate ligament rupture (CCLR) and medial patellar luxation (MPL), correcting both disorders is are essential for restoring normal gait. However, the previously described surgical treatment, using two osteotomy technique, poses a high risk of fracture and instability. Addressing CCLR and MPL with a single osteotomy and implant was considered superior to the conventional method. Therefore, a pre-contoured modified tibial plateau leveling osteotomy (PCM-TPLO) plate facilitating medial shifting of the proximal tibia was developed. We compared postoperative alignment and strength between this novel plate group and a conventional tibial plateau leveling osteotomy (TPLO) plate group using eight small-breed dog cadavers each. Additionally, we investigated the potential of the novel plate as an alternative to tibial tuberosity transposition. Postoperative alignment and strength were assessed through radiographs and mechanical testing. Measurements including tibial plateau angle, mechanical medial proximal tibial angle, and number of screws within the joint were also analyzed. There were no significant differences in all measured parameters. For the novel plate, the medial displacement ratio of the proximal tibia was confirmed to be approximately 30%, and the result was thought to be appropriate. These findings suggest that the PCM-TPLO plate could be a promising alternative for treating concurrent CCLR and MPL in small-breed dogs.

Abnormal lateral meniscal signal in MRI after patellar dislocation does not indicate a meniscal tear: MR findings with surgical correlation.

Background: Combined injuries observed with first-time lateral patellar dislocation (LPD) of the knee, particularly significant soft tissue injury, can inform surgical intervention criteria. Purpose: The purpose of this study was to compare MRI findings in LPD to surgical correlation concerning meniscal pathology as a guide for surgical management. Study design: Retrospective case series, Level of evidence, 4. Methods: A retrospective review was conducted of 355 cases of patients with lateral patellar dislocation from 2012 to 2022. Imaging was reviewed by musculoskeletal radiologists blinded to surgical results for evidence of soft tissue injury, and associated arthroscopic data and operative reports were reviewed. Results: Out of 44 cases of LPD in 42 patients who underwent MPFL reconstructive surgery, 27 (61%) cases had grade 2a or higher signal changes in the anterior horn of the lateral meniscus, of which 10 (23%) had grade 3 signal changes. There were zero cases of meniscal tear in these cases upon review of operative reports and arthroscopic images. Conclusion: MRI findings of signal alterations in the lateral meniscus post-LPD may not indicate an actual tear. This could aid in surgical decision-making in primary LPD management.

Are short term outcomes superior following total knee arthroplasty when infra-patellar fat pad is resected? A systematic review and meta-analysis.

BACKGROUND: Data suggests the infra-patellar fat pad (IPFP) is resected in the majority of total knee arthroplasty cases. Current literature suggests there may be scope for increasing preservations rates. A systematic review and meta-analysis of available literature was performed to assess if resection of IPFP resulted in superior patient outcomes. METHODS: Scopus, PubMed, Cochrane, Embase and CINAHL were systematically searched in February 2024 for articles of relevance and meta-analysis conducted. A standardized mean difference and confidence interval of 95% was calculated. An odds ratio was calculated for all included datasets. Heterogeneity was assessed for using the I2 statistic. RESULTS: Thirteen studies were included within this review. IPFP resection shortened the patella tendon at 6 months post-operatively (OR, 0.07; 95% CI, 0.02-0.12, P = 0.006). Results favoured preservation at 12 months post-operatively (OR, 0.02; 95% CI, -0.02 to 0.06, P = 0.32). Oxford Knee Society (OKS) results statistically favoured preservation at 6 months (OR, 1.57; 95% CI, 0.74-2.39, P = 0.0002). Findings at 12 months favoured resection (OR, -0.49; 95% CI, -5.39, 4.41, P = 0.84). Resection increased anterior knee pain at 6-12 months post-operatively (OR, 1.45; 95% CI, 1.12-1.89, P = 0.005). Combined subgroup analysis of flexion favoured resection (OR, -2.15; 95% CI, -6.52 to 2.22, P = 0.34). CONCLUSION: OKS and patella tendon length results favoured preservation at 6 months however did not reach minimal clinically important difference. Combined subgroup analysis of flexion did not yield a statistically significant result. Rates of anterior knee pain at 6-12 months favoured preservation.

Recurrent cyclops lesion after primary resection of fibroreactive nodule following anterior cruciate ligament reconstruction.

In this case report featured in World Journal of Orthopedics, Kelmer et al describe a rare finding of a 28-year-old female patient who presented with a recurrent fibroreactive nodule 7 months following the resection of a primary cyclops lesion, suggesting recurrent cyclops syndrome. The patient had undergone an initial anterior cruciate ligament reconstruction for a non-contact right knee injury and reported successful recovery. Two years later, the patient sustained a repeat right knee injury followed by a positive McMurray test and acute pain with terminal extension. Arthroscopic synovectomy confirmed magnetic resonance imaging (MRI) finding of a cyclops lesion, which was surgically removed. Seven months postoperatively, the patient reported stiffness and difficulty with terminal extension. Repeat MRI indicated a recurrent cyclops lesion, which was surgically resected. Following resection of the second lesion, the patient underwent physical therapy and achieved full range of motion, maintaining complete recovery 19 months postoperatively. Recurrent cyclops lesions have rarely been reported in the literature, and this article is novel in its report of recurrent cyclops syndrome following a bone-patellar tendon-bone allograft. The presentation of this unusual finding exposes a need for further investigation of cyclops lesion pathology, which will aid its prevention and treatment.

Collagen-Type Composition in the Semitendinosus, Quadriceps, and Patellar Tendons of a 22-Year-Old Patient: A Case Report.

Graft failure is a common postoperative complication after anterior cruciate ligament (ACL) reconstruction. Recently, a theory has emerged that histological and microstructural factors of autografts may be related to graft failure. We simultaneously collected the semitendinosus tendon (ST), quadriceps tendon (QT), and patellar tendon (PT) from a 22-year-old patient to provide insights into the differences in the collagen-type composition of the three tendons in skeletally mature patients. These findings may serve as a basis for selecting autografts for ACL to reduce graft failure rates. The patient was a 22-year-old female who required the removal of artificial ligament, screws, and washers and medial patellofemoral ligament (MPFL) reconstruction with an ST autograft after two surgeries for recurrent dislocation of the left patella. The ST, QT, and PT obtained during necessary intraoperative procedures were used as samples. The tissues were processed and immunostained; this was followed by confocal microscopy. Evaluation was performed by calculating the percentage of areas positive for collagen types I and III.The percentage of type I collagen in the ST, QT, and PT groups was 88%, 85%, and 88%, respectively.The collagen-type composition was examined following simultaneous collection of the ST, QT, and PT. The results revealed no significant differences in the content of physically strong type I collagen, which supports previous findings showing that the clinical outcomes after ACL reconstruction do not vary with the autograft used.

Does Patellar Denervation with Electrocautery Benefits for Total Knee Arthroplasty without Patellar Resurfacing: A Meta-analysis of Randomized Controlled Trails.

To investigate the effects of patellar denervation (PD) and non-patellar denervation (NPD) after primary total knee arthroplasty (TKA) without patellar resurfacing, this study conducted systematic electronic searches in November 2023 using PubMed, Embase, Web of Science, Cochrane, and Scopus, adhering to Cochrane Collaboration recommendations. Only randomized controlled trials (RCTs) were included. Additionally, a manual search was performed to identify potentially eligible studies from the reference lists of review articles. Two researchers independently conducted literature reviews, data extraction, and risk of bias assessments. The outcome analysis encompassed the incidence of anterior knee pain (AKP), visual analogue scale (VAS), range of motion (ROM), American Knee Society Score (KSS), Oxford Knee Score (OKS), patellar score (PS), complications, and reoperations. Meta-analysis was executed using RevMan 5.3 software. To enhance the credibility of the study, TSA v0.9 software was utilized to perform power analysis on the overall efficacy of primary and secondary outcomes. Twelve studies involving 1745 patients (1587 knees) were included, with 852 undergoing PD and 893 undergoing NPD. Results indicated a superior reduction in AKP incidence in the PD group compared to the NPD group. Statistically significant differences were observed between PD and NPD in KSS, OKS, and PS. However, the upper limit of the 95% confidence interval for each outcome fell below the minimal clinically important difference (MCID). No significant differences were found in VAS and ROM between PD and NPD. Additionally, PD was not associated with an increased incidence of complications or reoperations. Within 12 months and beyond, PD was proven to be a beneficial intervention in reducing AKP following TKA without patellar resurfacing, achieved without an increase in complications or reoperations. Regarding KSS, OKS, and PS, the minimal advantage achievable through PD may not be clinically significant.

Modified Z-plasty of the Patellar Ligament with Reinforcement of the Quadriceps Tendon in the Treatment of Patella Baja.

Patella baja is an infrequent knee pathology, but it is limiting due to joint stiffness and localized pain in the anterior region of the knee. It may occur after trauma, prolonged immobilization or local surgical intervention. The striking pathological finding is the shortening and increase in thickness of the patellar ligament. Several surgical techniques have been described for its treatment, and there is no standardized treatment. We describe the case of a 73-year-old female patient who presented with knee stiffness, significant functional deficit, and patella baja after total knee arthroplasty. She underwent a recently described soft tissue surgical procedure, with excellent functional evolution, improving from a Lysholm Knee Score of 16 to 81 points, allowing early mobilization and return to daily life activities.

Kinematical alignment better restores native patellar tracking pattern than mechanical alignment.

PURPOSE: The purpose of this study was to assess whether kinematic alignment (KA) outperforms mechanical alignment (MA) in restoring patellar tracking to native patterns by using a clustering algorithm. METHODS: Twenty cadavers (40 knees) were evaluated. For each cadaver, one knee was randomly assigned to KA and the other to MA. KA total knee arthroplasty (TKA) procedures were performed using a caliper-verified technique, while MA TKA procedures utilized a measured resection technique. Subsequently, all specimens were mounted on a customized knee-testing system, and patellar tracking was measured using a motion analysis system. All patellar tracking data were clustered using the density-based spatial clustering of applications with noise algorithm. Differences in patellar tracking patterns and the restoration of native patellar tracking were compared between the two alignment strategies. RESULTS: Patellar tracking patterns following KA were considerably different from MA. Pre- and post-TKA patellar tracking patterns following MA were grouped into separate clusters, whereas a substantial proportion of patellar tracking patterns following KA were grouped into the pre-TKA dominant cluster. Compared to MA, a greater proportion of patellar tracking patterns following KA showed similar patterns to native knees (p < 0.05) and more patellar tracking patterns following KA paired with preoperative patterns (p < 0.01). CONCLUSION: KA restored native patellar tracking patterns more closely compared to MA. LEVEL OF EVIDENCE: Level I, therapeutic study.

Multifragment fracture of the patellar apex with extensive loss of skin: A case report.

Introduction: Patella fractures account for 1 % of all skeletal fractures, and can interrupt the knee's extensor apparatus. They can also be serious if associated with a cutaneous opening. We report the case of a fracture of the tip of the patella with a large loss of cutaneous substance. Case report: A 22-year-old man was admitted for the management of a left knee trauma following a motorcycle accident. Clinical examination revealed a large loss of skin substance on the anteromedial aspect of the knee, with exposed bone, pain and lack of extension of the left knee. Standard X-ray of the left knee showed an avulsion fracture of the tip of the patella. The patient underwent patellar tendon reconstruction using transosseous stitches, reinforced by a quadricipital tendon reversal plasty, and protected by steel-wire patellotibial cerclage. A medial gastrocnemius flap was used to cover the loss of skin substance. After a functional rehabilitation protocol, the functional results were satisfactory, with a full return to activity after six months. Conclusion: The stability of osteosynthesis using quadricipital tendon reversal plasty and patellotibial cerclage allows mobilization and immediate weight-bearing. This may lead to better clinical results.

The Influence of Different Hamstrings Assemblies on the Final Graft Diameter in Anterior Cruciate Ligament Reconstruction.

Objective This study aimed to compare gracilis and semitendinosus tendon graft diameters in anterior cruciate ligament (ACL) reconstruction using quadruple, quintuple, and sextuple assemblies. Another objective was to evaluate the percentage of patients in which each assembly type is possible, depending on the length of each free tendon. Methods Seventy-one patients underwent ACL reconstruction using hamstring tendons. We measured the diameters of the quadruple, quintuple, and sextuple assemblies in all patients. We recorded tendon length and graft diameter from three assembly types. Results Assembly comparison showed a statistically significant difference ( p < 0.001). In each assembly, graft diameter increased by 1 mm, a statistically significant value ( p < 0.001). In 2.8% of patients, the only potential assembly was the quadruple assembly because the free lengths of the 2 tendons removed were lower than 24 cm. The quintuple assembly was possible in 23.9% of subjects, as only the semitendinosus had a minimum length of 24 cm. The sextuple assembly was possible in 73.2% of patients because both tendons were at least 24 cm in length. Conclusion A quintuple or sextuple assembly is possible in 97.2% of cases since the final graft length of at least 8 cm is statistically significant between comparisons.

Patellar Tendon Reconstruction Using Tibialis Posterior Allograft for Treatment of Patellar Tendon Rupture After Bone-Patellar Tendon-Bone Anterior Cruciate Ligament Reconstruction.

Background: Bone-patellar tendon-bone (BPTB) autografts are often used to treat anterior cruciate ligament (ACL) tears in young, highly active patients. These grafts are robust and provide adequate stability, allowing for return to sport and optimal functional outcomes in athletes. Patellar tendon rupture following BPTB ACL reconstruction is rare and can be difficult to treat. Case Report: A 19-year-old collegiate wrestler injured his left knee during a match. On evaluation 7 days after the injury, he was found to have increased anterior translation of the tibia on Lachman testing and an abnormal pivot shift. Magnetic resonance imaging demonstrated a complete tear of the ACL, and he successfully underwent a BPTB ACL reconstruction without complication. He progressed appropriately in the acute postoperative period. Six weeks after his index surgery, the patient reinjured his left knee and was diagnosed with a patellar tendon rupture. The previously reconstructed ACL was intact. A posterior tibialis tendon graft was used to repair the patellar tendon via a transosseous tunnel in the tibial tuberosity. The patient's recovery was complicated by a superficial wound that resolved with treatment. He achieved full range of motion and was able to return to sport. Conclusion: No technique for treating patellar tendon rupture following BPTB ACL reconstruction has been widely accepted. The treatment of this injury is left to the preference of the surgeon. This case demonstrates that tibialis posterior allografts are a viable option for the treatment of such injuries.

Three different patellar fixation techniques yield similar clinical and radiological outcomes in recurrent patellar dislocation undergoing medial patellofemoral ligament reconstruction.

PURPOSE: The purpose of this study was to evaluate and compare the clinical and radiological outcomes of three different patellar fixation techniques on medial patellofemoral ligament reconstruction (MPFLR) in the treatment of patellar dislocation (PD). METHODS: Between 2015 and 2020, 130 patients with recurrent PD who underwent surgical reconstruction were eligible for this retrospective study: 48 patients were treated with the semi-tunnel bone bridge fixation technique (Group A), 42 patients were treated with the suture anchor fixation technique (Group B) and 40 patients were treated with the transpatellar tunnel fixation technique (Group C). Clinical outcomes included functional outcomes (Kujala, Lysholm and International Knee Documentation Committee scores), activity levels (Tegner activity score and return to sports), physical examinations, patellar re-dislocation rate and complications. Radiological outcomes included patellar congruence angle, patellar tilt angle, lateral patellar translation and lateral patellar angle. RESULTS: All clinical and radiological outcomes improved significantly in all groups, without any significant difference among these three groups. At the final follow-up, no re-dislocation occurred, and all groups achieved a successful return to sports. However, the semi-tunnel bone bridge and suture anchor fixation techniques showed statistically higher Tegner activity scores (p = 0.004) and shorter time from surgery to return to sports (p = 0.007) than the transpatellar tunnel fixation technique. CONCLUSION: The three MPFLR patellar fixation techniques achieved favourable and comparable clinical and radiological outcomes in the treatment of PD. Compared with the transpatellar tunnel fixation technique, the semi-tunnel bone bridge and suture anchor fixation techniques may be more effective with higher activity levels. LEVEL OF EVIDENCE: Level III.

Early Postoperative Rapid Rehabilitation Yields More Favorable Short-term Outcomes in Patients Undergoing Patellar Realignment Surgery for Recurrent Patellar Dislocation: A Prospective Randomized Controlled Study.

BACKGROUND: Use of a rapid rehabilitation protocol for postoperative recovery after recurrent patellar dislocation (RPD) has gradually gained attention; nonetheless, evidence of its safety and effectiveness is lacking. PURPOSE: To compare the short-term postoperative outcomes of early rapid rehabilitation with those of conservative rehabilitation in patients with RPD. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: A total of 50 patients with RPD who underwent tibial tubercle osteotomy combined with medial patellofemoral ligament reconstruction were enrolled between January 2018 and February 2019. Postoperatively, the patients were randomly assigned to either the early rapid group (rapid group; n = 25 patients) or the conservative group (control group; n = 25 patients) for rehabilitation training. The rapid group underwent faster progression in weightbearing and range of motion (ROM) training. Knee joint functional scores, ROM, bilateral thigh circumference differences, and imaging data were recorded preoperatively and at 6 weeks and 3, 6, 12, and 24 months postoperatively for comparison. Postoperative complications were recorded over the 24-month follow-up period. RESULTS: The baseline data did not significantly differ between the 2 groups. Postoperatively, compared with the control group, the rapid group had higher Tegner scores at 6 weeks and 3 months; higher Lysholm scores at 3 and 6 months; higher International Knee Documentation Committee scores at 6 weeks, 3 months, and 12 months; better ROM; and smaller bilateral thigh circumference differences at 24 months (P < .05 for all). However, no differences were observed in the Tegner, Lysholm, and International Knee Documentation Committee scores at 24 months postoperatively. At the 6-week and subsequent follow-up visits, the Caton and Insall indices were lower in the control group than in the rapid group (P < .01 for all). Moreover, compared with the control group, the rapid group had a lower incidence of patella baja at 24 months (0% vs 17%) and fewer complications during the whole follow-up period (P < .01). CONCLUSION: Early rapid postoperative rehabilitation appears to be safe and effective for patients who undergo tibial tubercle osteotomy combined with medial patellofemoral ligament reconstruction to treat RPD. In the short term, this approach was shown to be more advantageous than conservative rehabilitation in improving functional scores, allowing an earlier return to daily activities, although the lack of difference at 24 months implies no long-term benefits. In addition, it potentially helped to prevent the occurrence of complications, including patella baja. REGISTRATION: ChiCTR1800014648 (ClinicalTrials.gov identifier).

An evaluation of a novel method for the MRI-based assessment of Caton-Deschamps index in the Knee.

INTRODUCTION: The radiographical assessment of patella height has historically been performed using X-Ray. The aim of this study was to evaluate a new method for the assessment of patella height using MRI and to assess the correlation with the X-Ray based assessment. MATERIALS AND METHODS: 159 patients who had both lateral radiographs and MRI images were included. Parameters measured included traditional radiographical CDI, MRI-based CDI, and TT-TG distance. On the basis of the TT-TG, the patients were divided into 2 groups. Two different methods were used to assess CDI using MRI: using a single slice image, and an alternative technique using two different cross-sectional images. The correlation of the two measurement methods was assessed using Pearson's correlation coefficient. The intraclass correlation coefficient (ICC) was determined from the measurements of the two investigators. RESULTS: The average TT-TG distance was 11.6 mm (± 4.6). In patients with a TT-TG < 15 mm, both measurement methods showed comparable correlation with measurements on X-Ray. In patients with a TT-TG of > 15 the the new cross-sectional imaging method showed higher correlation with traditional X-Ray assessment compared to CDI assessment using the traditional single slice method (r = 0.594, p < 0.001 vs. r = 0.302, p = 0.055). CONCLUSIONS: The assessment of CDI on MRI using a cross-sectional imaging method has a better correlation with traditional X-Ray assessment of CDI than single-slice assessment. This is particularly true in patients with elevated TT-TG and as such should be preferentially used in the assessment of Patellar height in this cohort.