Combination of the medial patellofemoral ligament reconstruction with the quasi-anatomic technique, tibial tuberosity osteotomy, lateral retinaculum release and mosaicplasty produces satisfactory results for patients with patello-femoral instability. 2-Year follow-up.

INTRODUCTION: This study aimed to evaluate the effectiveness and safety of a combined surgical approach for treating complex patellofemoral instability. This approach combines four procedures: medial patellofemoral ligament (MPFL) reconstruction with the quasi-anatomic technique, lateral retinaculum release, anteromedialization and distalization of tibial tuberosity and patellar/femoral mosaicplasty. MATERIAL AND METHODS: Between August and November 2021, we enrolled 27 patients in the study (21 females, 6 males, average age 28.6 years). All with patella alta, recurrent patellar instability, severe cartilage focal damage, and increased tibial tubercle-trochlear groove distance. All underwent the combined procedure during this period. We assessed their pain and functional scores before surgery and at 6, 12, and 24 months after surgery using standardized scoring systems. RESULTS: Patients initially reported significant pain and functional limitations. However, at 24 months, their pain scores significantly reduced, averaging 1.5 compared to 8.2 pre-surgery. Similarly, their functional scores substantially improved, with Lysholm, Tegner, Kujala, BPII scores reaching 87.44, 8.44, 90.03, 86.07 compared to 56.4, 3.7, 42.48, 23 pre-surgery, respectively. Importantly, no cases of recurrent instability occurred, and 96.3% of patients reported complete satisfaction. CONCLUSIONS: This combined surgical approach has a high rate of success for patients with patella alta, recurrent lateral patellar instability, severe focal chondral lesions, and increased TT-TG distance. Moreover, 26 out of 27 patients (96.3%) reported total satisfaction. Therefore, we conclude that although this procedure combination is not simple, it is a safe, reproducible, and alleviates pain at 24 months postoperatively, and significantly improves functional scores.

Isolated Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability Regardless of Tibial Tubercle-Trochlear Groove Distance and Patellar Height: Minimum 5-Year Outcomes.

BACKGROUND: It remains unclear which subset of patients with recurrent patellofemoral instability would benefit from a concomitant bony realignment procedure in addition to a medial patellofemoral ligament (MPFL) reconstruction. PURPOSE: To provide midterm results for patients who underwent an isolated MPFL reconstruction as part of an ongoing prospective trial. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients with recurrent patellar instability were prospectively enrolled in an institutional registry beginning in March 2014. Exclusion criteria included history of a previous surgery for patellar instability, an off-loadable (inferior/lateral) chondral defect, anterior knee pain ≥50% of their chief complaint, and a "jumping J" sign. All patients underwent primary, unilateral, isolated MPFL reconstruction regardless of their bony anatomic characteristics. Patient-reported outcome measures (PROMs), episodes of recurrent instability, and ability to return to sport were obtained annually. Radiographic measurements of baseline radiographs and MRI were obtained at baseline. RESULTS: A total of 138 patients underwent isolated MPFL reconstruction between March 2014 and December 2019. The mean radiographic measurements were tibial tubercle-trochlear groove, 15.1 ± 4.9 mm; Caton-Deschamps index, 1.14 ± 0.16; patellar trochlear index, 46.9% ± 15.1%; trochlear depth index, 2.5 ± 1.2 mm; tibial tubercle to lateral trochlear ridge, -8.4 ± 5.7 mm; and patellar tendon to lateral trochlear ridge, 5.7 ± 6.2 mm. Trochlear dysplasia, defined as a trochlear depth index <3 mm, was present in 79/125 (63%) patients. A total of 50 patients reached ≥5 years, of whom 40 (80%) completed follow-up PROMs. A total of 119 patients reached ≥2 years, of whom 89 (75%) completed follow-up PROMs. Six patients (5%) reported recurrent instability with a mean time of 2.97 years after surgery. All PROMs improved over time except for the Pediatric Functional Activity Brief Scale (Pedi-FABS), which had no change. At 2 years, the mean changes from baseline for Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life subscale (QOL), Pedi-FABS, International Knee Documentation Committee (IKDC) score, KOOS Physical Function Short Form (PS), and Kujala score were 42.1, 0.6, 35.1, -23.5, and 32.3, respectively. All changes had P values <.001 except for Pedi-FABS, which showed no change and had P > .999. At 5 years, the mean changes from baseline for KOOS-QOL, Pedi-FABS, IKDC, KOOS-PS, and Kujala score were 42.6, -2.8, 32.6, -21.5, and 31.6, respectively. All changes had P values <.001 except for Pedi-FABS, which showed no change and had P > .453. In total, 89% of patients returned to sport with a mean of 9.1 months. CONCLUSION: Midterm outcomes for patients who underwent isolated MPFL reconstruction were favorable and were maintained at 5 years. Outcomes for the expanded cohort of patients with a minimum 2-year follow-up support previously published results.

Readability and Reliability of Online Information Regarding Patellar Instability.

BACKGROUND: Assessment of readability and reliability of online resources for orthopedic patients is an area of growing interest, but there is currently limited reporting on this topic for patellar instability (PI) and medial patellofemoral ligament reconstruction (MPFLR). METHODS: Utilizing the Searchresponse.io dataset, we analyzed inquiries related to PI and MPFLR. Readability and reliability were assessed using the Automated Reading Index, Flesch Reading Ease, and the JAMA benchmark criteria. RESULTS: Analysis of 363 frequently asked questions from 130 unique websites revealed a predominant interest in fact-based information. Readability assessments indicated that the average grade level of the resources was significantly higher than the 6th grade level and reliability varied between resources. CONCLUSION: Although the internet is an easily accessible resource, we demonstrate that PI and MPFLR resources are written at a significantly higher reading level than is recommended, and there is inconsistent reliability amongst resources with medical practice websites demonstrating the lowest reliability.

Minimal invasive medial patellofemoral ligament reconstruction using quadriceps tendon with de novo technique and arthroscopic guided: A case report.

INTRODUCTION: Medial Patellofemoral ligament (MPFL) reconstruction, the primary procedure for restoring patellar stability and preventing further dislocation, has seen numerous methods and grafts. However, a consensus on the technique and graft remains elusive. This study introduces a novel approach to MPFL reconstruction, utilizing a unique combination of minimal invasiveness, de novo method, and arthroscopic guidance to harvest a quadriceps tendon (QT) graft without the need for a harvesting tool. CASE ILLUSTRATION: A 37-year-old female presented to the emergency room with the chief complaints of left knee pain and swelling following the third spontaneous dislocation of the patella. The patient had a few episodes of locking sensation and instability of the left knee while walking, especially while climbing stairs. A knee MRI revealed MPFL tear in the left knee. A modified minimal invasive MPFL reconstruction technique was performed. The IKDC, Lysholm, and Modified Cincinnati scores improved significantly from preoperatively 48.3 %, 49 %, and 51 % to 89.7 %, 90 %, and 95 % consecutively. No recurrent patellar dislocations or swelling were reported during follow-up. DISCUSSION: While quadriceps graft harvesting for MPFL reconstruction is typically highly invasive, using quadriceps tendons has consistently shown excellent outcomes. This study, however, takes it a step further by demonstrating that a minimally invasive procedure for harvesting quadriceps tendons, even without specialized instrumentation, can also yield excellent results. CONCLUSION: MPFL reconstruction using superficial quadriceps tendon autograft can be achieved using a minimally invasive technique without the use of specialized instrumentation and has shown excellent knee functional improvement.

Medial patellofemoral ligament injury. Location-based rate of recurrent patellar dislocation after non-operative treatment.

OBJECTIVES: The role of the medial patellofemoral ligament (MPFL) as a patellofemoral joint stabilizing structure is undisputable. After traumatic patellar dislocation, MPFL injury, together with bone edema in the medial patellar facet and lateral femoral condyle, is a pathognomonic finding in magnetic resonance imaging (MRI). MPFL injury in the femoral insertion has been reported to most likely predict recurrent dislocations. The objective of this study was to detect if any MPFL injury location predicts the earliest onset of the patellar re-dislocation. METHODS: In total, 64 eligible patients with a first-time traumatic patellar dislocation were recruited to the trial. The diagnosis was confirmed within 3 weeks with 3T magnetic resonance imaging. The location of the MPFL injury in MRI was localized at the patellar insertion, midsubstance area, femoral insertion, or a combination of these. During the three-year follow-up period, patellar re-dislocations, range of motion, quadriceps muscle atrophy, and daily symptoms were determined. All the patients were treated non-operatively. RESULTS: Out of 64 patients, 33 (51.6%) had at least one episode of patellar re-dislocation. Re-dislocations occurred in 8 out of 25 (32.0%) patients with the main injury at the femoral insertion, 5 out of 15 (33.3%) patients with the main injury at the midsubstance area, and 10 out of 24 (41.7%) patients with the main injury at the patellar insertion during the 36 months follow-up (p â€‹= â€‹0.758). According to Kaplan-Meier analysis, the location of MPFL injury did not have any statistically significant effect on the timing of re-dislocations. At 36 months, survival of patients with MPFL injury at the patellar insertion was 70.8%, which was not statistically significantly different than the survival in patients with injury at the femoral insertion (88.0%) or at the midsubstance area (93.3%). No differences between single and multiple MPFL injuries were found. At 4 weeks, the range of motion was more restricted in patients with MPFL injury at the femoral insertion (93.4° vs. 108.0° for injury at the midsubstance area and 107.7° at the patellar insertion). CONCLUSION: The location of MPFL injury did not have any statistically significant effect on timing or the rate of re-dislocations. The MPFL injury at the femoral insertion predicts decreased range of motion (ROM) of the knee and increased quadriceps muscle atrophy during the first three months after sustaining injury. LEVEL OF EVIDENCE: Level III.

Comparison of Clinical Outcomes After Medial Patellofemoral Ligament Reconstruction With Allograft Versus Autograft: A Matched-Cohort Analysis.

Background: Disruption of the medial patellofemoral ligament (MPFL) may lead to recurrent lateral patellar dislocation and patellofemoral chondral injury. Despite significant previous work investigating numerous performance parameters, the optimal graft choice for MPFL reconstruction for patellar instability remains unclear. Purpose: To compare functional outcomes scores, subjective recurrent instability, and revision rates between autograft and allograft in MPFL reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: Patients who underwent MPFL reconstruction with autograft between 2013 and 2018 were identified. A 2:1 comparison group of patients who underwent MPFL reconstruction with allograft was matched by sex, age (±3 years), and body mass index (BMI) (±3 kg/m2). Patient characteristics, preoperative radiograph measurements, and intraoperative data were compared between the groups, as were patient-reported outcome measures, including International Knee Documentation Committee (IKDC) score, Lysholm score, Single Assessment Numerical Evaluation (SANE), and visual analog scale (VAS) for pain. Subjective recurrent instability and revision rate were also compared between groups. Results: The autograft group was composed of 30 patients (13 male, 17 female) with a mean age of 24.4 years and mean BMI of 25.0 kg/m2, and the allograft group was composed of 60 matched patients (25 male, 35 female) with a mean age of 24.1 years and mean BMI of 25.1 kg/m2. The autograft and allograft groups reported similar IKDC scores (73.0 vs 73.7; P = .678), Lysholm scores (77.5 vs 80.7; P = .514), SANE (72.0 vs 75.8; P = .236), and VAS pain (30.7 vs 26.6; P = .482), as well as similar rates of postoperative patellar subluxations (20.0% vs 19.3%; P = .867) and dislocations (10.0% vs 15.0%; P = .805). Conclusion: Both allograft and autograft were found to be viable options for MPFL reconstruction. There were no significant group differences in failure rates, patient-reported outcomes, pain, or complications between autograft and allograft MPFL reconstruction in this series.

Lateral to medial fluoroscopic view improves the accuracy of identifying the MPFL femoral footprint using Schottle's technique.

PURPOSE: This study investigated the effect of different fluoroscopy settings on the accuracy of locating Schottle's point during medial patellofemoral ligament (MPFL) reconstruction. METHODS: The centre of the MPFL femoral footprint was identified and marked on 44 dry femurs. Two standard true lateral knee fluoroscopic images were obtained: (1) medial to lateral (ML) and (2) lateral to medial (LM). The deviation between the anatomically determined MPFL femoral footprint and the fluoroscopically identified point was measured on both fluoroscopic images. An 'acceptable tunnel location' was defined as within a 5- or 7-mm margin of error from the anatomic MPFL footprint. Distal femoral morphometric dimensions were also measured using digital calipers. Statistical analysis determined discrepancies between techniques and their relation to femoral morphometry. RESULTS: The LM view yielded a significantly smaller distance between the anatomical MPFL footprint and Schottle's point compared to the ML view (3.2 ± 1.5 vs. 4.5 ± 2.1 mm, p < 0.001). The LM view achieved acceptable tunnel locations, meeting the 5-mm error criterion in 90.9% of cases, while the ML view achieved 65.9% (p < 0.001). Both views yielded acceptable tunnel locations at similar rates using the 7-mm error criterion (n.s.). The anatomic MPFL footprint was displaced towards the anterior and proximal location in the ML view in reference to the Schottle point. No correlation was observed between any of the morphometric measurements and the deviations. CONCLUSIONS: This study demonstrated that using the LM fluoroscopic view improves the accuracy of femoral tunnel placement when identifying the MPFL footprint via the Schottle technique. Adopting the LM view in surgical practice will help surgeons locate the anatomical femoral footprint accurately, replicating the native MPFL and enhancing clinical outcomes. LEVEL OF EVIDENCE: Level 4, cadaveric study.

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.

Sulcus-deepening trochleoplasty grants satisfactory results with minimal patellofemoral arthritis at 23-30 years of follow-up.

PURPOSE: The purpose of this study was to evaluate the radiographic and clinical outcomes of sulcus-deepening trochleoplasty at a minimum follow-up of 23 years. METHODS: The authors evaluated a retrospective series of 10 patients (11 knees) who underwent trochleoplasty between 1993 and 2000. All patients were assessed at a minimum follow-up of 23 years by an independent clinician who noted any patellar redislocations and collected the International Knee Documentation Committee (IKDC), Kujala scores and range of motion. Radiographic examination was performed to assess patellofemoral arthritis using the Iwano classification. RESULTS: A total of 11 knees, from five women and five men aged 25.6 ± 6.9 years (range, 15-47 years) underwent trochleoplasty during the inclusion period. All 11 knees underwent adjuvant procedures during trochleoplasty (100%): 10 had tibial tuberosity osteotomy (TTO) and vastus medialis plasty and 1 had only vastus medialis plasty (had prior TTO). At a follow-up of 24.4 ± 2.1 years (range, 23-30 years), two patients were lost to follow-up (18%). The Iwano classification was Grade 1 in three patients (33%), Grade 2 in four patients (44%) and Grade 4 in two patients (22%). The flexion range was 130 ± 8.7° and satisfaction was 9.2 ± 0.7, Kujala was 76.9 ± 8.5 and IKDC was 65.5 ± 13.8. CONCLUSION: At 23-30 years following sulcus-deepening trochleoplasty in this small series of 10 patients (11 knees), patients had satisfactory clinical scores, only 1 patient reported an episode of traumatic patellar dislocation, and two knees had patellofemoral arthritis of Iwano Grade >2 (22%). LEVEL OF EVIDENCE: Level IV.

[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.

Is kinesiophobia associated with functional outcome measures in patients following medial patellofemoral ligament reconstruction?

BACKGROUND: This study aimed to investigate the potential relationship between kinesiophobia and functional outcomes in patients following medial patellofemoral ligament reconstruction (MPFLr). METHODS: Twenty-one patients (six males, 15 females) who underwent MPFLr between 2016 and 2020, (23.57 ± 9.49 years old) with a mean follow up period of 52.33 ± 24.82 months were included in the study. Following an assessment of patellar stability and alignment, kinesiophobia levels, function and balance were measured. The kinesiophobia was measured using the Tampa Scale of Kinesiophobia, while functional outcomes were assessed with the single-leg hop test, Y-Balance test and single-leg sway index. The self-reported function was measured by Kujala patellofemoral score and Lysholm knee score. RESULTS: The patients exhibited kinesiophobia scores of 43.10 ± 6.90. A negative correlation existed between kinesiophobia and both the Kujala scores (r = -0.75, P < 0.001) and the Lysholm scores (r = -0.79, P < 0.001). Moderate negative correlations were observed between kinesiophobia and the single-leg hop distance (r = -0.64, P < 0.01), as well as in Y-Balance test anterior reach distance (r = -0.51, P < 0.01) and posterolateral reach distance (r = -0.55, P < 0.01). Additionally, a low negative correlation was noted between kinesiophobia and Y-Balance test posteromedial reach distances (r = -0.43, P = 0.05), as well as the total sway index (r = -0.46, P = 0.04). CONCLUSIONS: A high level of kinesiophobia was strongly correlated with self-reported functional scores and moderately correlated with measured functional outcomes. The findings underscore a notable prevalence of kinesiophobia following biomechanically successful MPFLr. Investigating the impact of kinesiophobia on outcomes after MPFLr may provide a better understanding of patient recovery.

Promising results following derotational femoral osteotomy in patellofemoral instability with increased femoral anteversion: A systematic review on current indications, outcomes and complication rate.

Purpose: Patellofemoral joint instability (PFJI) can surgically be treated with a multitude of approaches, depending on the underlying pathology. In the presence of increased femoral anteversion, some authors have reported good results with a derotational distal femoral osteotomy (DeDFO). The purpose of the study was to investigate the indications, outcomes and complication rate of DeDFO for PFJI. Methods: A systematic review was performed according to the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses) by searching Medline, Embase, Web of Science and Cochrane Library databases through 1 December 2023. Included were levels 1-4 clinical studies of skeletally mature patients undergoing a DeDFO for PFJI irrespective of concomitant procedures. Study characteristics, indications, radiological and clinical outcomes, surgical technique and concomitant procedures, re-dislocation and complication rate were all analysed, as was methodological quality. Results: A total of 12 studies including 310 patients (325 knees) were included. Three studies were cohort studies, all others were case series. The mean patient age across the studies was 22 years, and the mean follow-up was 29.4 months. Femoral anteversion cut-off was between 20° and 30°. Every study included at least one concurrent soft tissue, bony or combined procedure. Across all studies, one case of re-dislocation was reported (0.3%) and four implant or osteotomy-related complications (1.2%) were reported. All studies reported a statistically significant increase in clinical scores. Conclusion: This systematic review of DeDFO for patellofemoral instability in the presence of increased femoral anteversion demonstrates promising clinical results and an extremely low dislocation and complication rate. The heterogeneity of the cut-off in anteversion and concomitant procedures, especially tibial tubercle osteotomy with seemingly identical results, indicates the need for high-quality evidence for treating patellofemoral instability. Based upon this systematic review, we strongly recommend that DeDFO be added to the 'menu à la carte' of PFJI. Level of Evidence: Level III Systematic Review.

Nonanatomical femoral tunnel positioning in isolated MPFL reconstruction is not associated with an increased risk of patellofemoral osteoarthritis after a minimum follow-up of 10 years.

PURPOSE: The association between the prevalence of patellofemoral arthritis (PFA) and femoral tunnel positioning following isolated medial patellofemoral ligament reconstruction (MPFLr) has not been well described. The aim of this study was to analyse the relationship between femoral tunnel positioning and the prevalence of PFA. METHODS: This was a single-centre study of patients undergoing an isolated MPFLr between 2006 and 2011 with a minimum of 10 years of follow-up. Outcomes assessed were the presence of PFA on radiographs, recurrence of instability requiring revision surgery and patient-reported outcomes, including Kujala, Tegner and IKDC scores. Tunnel positioning was assessed on postoperative radiographs using two radiographic methods: Schöttle's point and the grid method to localise the femoral tunnel. Patients were grouped based on tunnel positioning and compared. RESULTS: Fifty patients were analysed at a mean follow-up of 12.4 years. Thirty-three patients (66%) had a femoral tunnel position within 7 mm of Schöttle's point and 39 (78%) within the anatomic quadrant, with the most common location according to the grid method in D4 (28%) and E4 (26%), respectively. Thirty-seven patients (74%) had a satisfactory (>80 versus <80) Kujala score at long-term follow-up. None of the examined tunnel assessment methods demonstrated a significant relationship with Tegner, Kujala or International Knee Documentation Committee scores. Patients with a femoral tunnel position >7 mm outside Schöttle's point or were considered to be in a nonanatomic position were not significantly more likely to result in unsatisfactory Kujala scores at the last follow-up. Tunnel positioning and the other tested parameters were not found to be significantly associated with the development of PFA. CONCLUSION: No correlation between femoral tunnel position and risk of PFA or poor outcomes was observed in patients undergoing isolated MPFLr at long-term follow-up. The impact of femoral tunnel placement on long-term outcomes in patients with PFI may be less significant than originally considered. LEVEL OF EVIDENCE: Level IV.

Outcomes of surgical treatment of patellar instability in children with Down syndrome.

BACKGROUND: patellar instability is a relatively frequent musculoskeletal disorder in children with Down syndrome (DS). However, such a condition has seldom been studied in the literature, even less its surgical treatment. Different techniques have been offered for this condition; the evidence for surgical options is scarce and primarily based on case reports or case series with few patients and heterogeneous techniques. Given this background, we aimed to evaluate the outcomes of a uniform kind of surgical procedure for such a condition that combined lateral soft tissue release, medial patellofemoral ligament (MPFL) reconstruction (using a partial-thickness quadriceps tendon autograft), the Roux-Goldthwait procedure, and V-Y quadricepsplasty (if needed). MATERIALS AND METHODS: This retrospective study involved 11 skeletally immature patients (12 knees; 9 males and 2 females), 5.5 to 14.1 years of age, with DS who had patellofemoral instability (PFI) and were managed by this technique between October 2018 and March 2020. Preoperative radiography, CT scan, and MRI were performed to evaluate the physis status, lower limb alignment, patellar height, trochlear morphology, and any associated knee pathology. A functional knee assessment was done by using the Kujala score and the modified Lysholm score. RESULTS: The mean time of follow-up (± SD) was 47.7 ± 5.8 months (range: 39-56). Pre-operatively, the Kujala score (± SD) was 52.6 ± 14.3 (range: (31-74), and at final follow-up, it was 92.2 ± 4.4 (range: (88-98), showing a significant improvement (P < 0.001). The preoperative modified Lysholm score (± SD) was 54.3 ± 8.1 (range: 39-62), and at final follow-up it was 92.4 ± 5.3 (range: 82-96), showing a significant improvement (P < 0.001). All patients had a stable patella without a recurrence of instability and regained full ROM. There was no incidence of a patellar fracture or femoral physis injury. CONCLUSIONS: Our proposed technique of combined soft tissue procedures, including lateral soft tissue release, MPFL reconstruction (using a partial-thickness quadriceps tendon autograft), the Roux-Goldthwait procedure, and V-Y quadricepsplasty, was an effective method for treating patellar instability in children with DS while avoiding physeal injury and patellar fracture. Functional scores and radiological outcomes were improved. LEVEL OF EVIDENCE: IV; retrospective case series.

Simultaneous MPFL reconstruction and guided growth result in low rates of recurrent patellofemoral instability.

PURPOSE: Implant-mediated guided growth (IMGG) is used to address coronal plane deformity in skeletally immature patients. Few studies have reported on IMGG and simultaneous medial patellofemoral ligament (MPFL) reconstruction for paediatric patients with concurrent genu valgum and patellofemoral instability (PFI). This study aimed to report on the outcomes of these simultaneous procedures. MATERIALS AND METHODS: This was a retrospective review of paediatric patients undergoing simultaneous MPFL reconstruction and IMGG between 2016 and 2023. Mechanical lateral distal femoral angle (mLDFA), hip-knee-ankle angle (HKA) and mechanical axis deviation (MAD) were measured on full-length hip-to-ankle plain radiographs. Measurements were taken preoperatively, prior to implant removal and/or at final follow-up with minimum 1-year clinical follow-up. RESULTS: A total of 25 extremities in 22 patients (10 female) underwent simultaneous IMGG and MPFL reconstruction. The mean age at surgery was 12.6 ± 1.7 years. The mean duration of implant retention was 18.6 ± 11.3 months. Nineteen extremities (76%) underwent implant removal by final follow-up. Preoperative HKA corrected from a mean of 5.8 ± 2.3° to -0.8 ± 4.5° at implant removal or final follow-up (p < 0.001), with mLDFA and MAD similarly improving (both p < 0.001). HKA corrected a mean of 0.7 ± 0.9° per month, while mLDFA and MAD corrected a mean of 0.5 ± 0.6°/month and 2 ± 3 mm/month, respectively. At the time of implant removal or final follow-up, 88% of patients demonstrated alignment within 5° of neutral. Only one extremity experienced subsequent PFI (4%). For 14 patients who underwent implant removal with further imaging at a mean of 7.8 ± 4.9 months, only one patient (7%) had a valgus rebound to an HKA > 5°. CONCLUSION: Simultaneous MPFL reconstruction and IMGG provided successful correction of lower extremity malalignment with only one recurrence of PFI. This approach is a reliable surgical option for skeletally immature patients with genu valgum and PFI. LEVEL OF EVIDENCE: Level 4 case series.

Palpation and fluoroscopy are valid but unreliable for the assessment of femoral tunnel position after medial patellofemoral ligament reconstruction.

OBJECTIVES: The purpose of this study was to evaluate the validity and reliability of two techniques, palpation and fluoroscopy, for assessing medial patellofemoral ligament (MPFL) reconstruction femoral tunnel position accuracy. METHODS: Twenty-one fresh frozen cadaveric knees had an MPFL femoral tunnel drilled and filled with a metal screw. Tunnels were created in a nonstandard fashion to ensure the sample included a range of tunnel positions from poor to ideal. Six experienced sport medicine and arthroscopy surgeons evaluated the placement of the femoral tunnel by palpating the screw in relation to anatomic landmarks and by fluoroscopy related to Schöttle's Point. They evaluated 1) the accuracy of femoral tunnel placement, 2) the direction of tunnel error, and 3) the clinical acceptability of the tunnel position. Validity measures included sensitivity, specificity, and correlation to clinical acceptability, which were calculated for the palpation and fluoroscopic assessments. Reliability measures included interrater reliability (ICC 2,k) for femoral tunnel accuracy and percent agreement of the raters' tunnel direction assessment. RESULTS: The palpation method demonstrated a sensitivity of 0.79 and specificity of 0.84 for assessing the accuracy of femoral tunnel placement, while the fluoroscopic method showed a sensitivity of 0.83 and specificity of 0.92. Pearson correlation coefficients for clinical acceptability of tunnel position were high, with both techniques ranging from .589 to .854. Interrater reliability for the palpation and fluoroscopic techniques for assessment of tunnel accuracy were 0.31 and 0.55 (ICC 2,k), respectively. Assessment of the direction of tunnel error was good with the fluoroscopic technique slightly more accurate than palpation. CONCLUSION: This study demonstrated that both palpation and fluoroscopy are valid techniques for assessing femoral tunnel position after MPFL reconstruction. Despite demonstrating good validity, the accuracy of assessing tunnel position was unreliable in a group of six experienced knee surgeons. Further research into MPFL reconstruction femoral tunnel assessment techniques, including patient-specific reference standards, is warranted. LEVEL OF EVIDENCE: Level 2.

Peracetic acid sterilized tendon and ligament allografts for knee reconstruction : For anterior cruciate ligament (ACL), posterior cruciate ligament (PCL) and complex knee surgery.

BACKGROUND: The use of allografts and autografts has been met with mixed views on whether allografts are a suitable alternative to autografts. QUESTION: We aimed to investigate if chemically sterilized allografts show similar rerupture rates to those reported in the literature for allografts and autografts in anterior (ACL) and posterior cruciate ligaments (PCL) and complex knee surgery. MATERIALS AND METHODS: Retrospective data on knee reconstructions performed between 2011 and 2015 with tendon/ligamnet allografts sterilized with peracetic acid were collected in the form of a questionnaire. The inclusion criteria of 2 years for each patient were met by 38 patients, representing 22 ACL reconstructions, 5 PCL reconstructions, 3 OTHER surgeries, including the Larson technique and medial patellofemoral ligament (MPFL) reconstruction and 8 COMPLEX surgeries. The main endpoints were rerupture and complication rate. Secondary endpoints included stability of the knee (Lachman test, Pivot shift test) and the range of motion. RESULTS: The rerupture rate was 7.9% (3 grafts). Reruptures only occurred in the ACL group. No reruptures were observed in the PCL, OTHER and COMPLEX surgery groups. Stability improved significantly after surgery and the range of motion returned to values similar to that of healthy knees. CONCLUSIONS: Tendon allografts sterilized with peracetic acid show promising low rerupture rates and good clinical scores and the results are comparable to the literature on autografts and other allografts.

Prospective assessment of functional and clinical results of surgical patellar stabilization in rural and urban populations. Equal chance to success?

INTRODUCTION AND OBJECTIVE: Patella dislocation represents 3.3% of all knee injuries often leading to persistent instability. Medial patello-femoral ligament(MPFL) reconstruction is the standard method of treatment in the patellar instability. Rehabilitation after MPFL-R is a long and demanding procedure. The hypothesis presented reflects the idea that despite relatively good access to hospital care and surgical options, the post-operative rehabilitation care system is still inferior in rural areas versus the one offered in major cities and towns. MATERIAL AND METHODS: Between January 2015 - January 2018, 47 patients met the study inclusion criteria, diagnosed and operated on due to patellar instability. 8 patients were lost for full follow-up. Finally, 39 patients were included, divided into two groups - group A (19 from cities), group B (20 from rural area). Prospective KOOS and Kujala scales assessments were conducted: preoperative, 6 and 12 months after surgery. Knee isokinetic muscle strength was measured at 3 stages; prior to surgery, 6 and 12 months after reconstruction. RESULTS: All patients showed significant improvement measured in the KOOS and Kujala scales after the procedure, compared to the pre-operational results. Despite equal clinical improvement, patients from Group A(city) achieved better functional outcomes as presented in the results of knee extensor functional tests using a Biodex dynamometer. CONCLUSIONS: Rehabilitation after MPFL reconstruction improves muscle strength and clinical outcome. Patients from rural areas had inferior functional results in comparison to the patients from major cities, even 12 months after surgical patella stabilization. Despite the development of roads and transport according to the EU cohesion policy, there are still differences in rehabilitation results between rural and city areas.

The 100 Top-Cited Articles on Medial Patellofemoral Ligament: A Bibliometric Analysis and Review.

Background: The medial patellofemoral ligament (MPFL) has been investigated widely in the past 30 years, resulting in many research achievements in this field. Purpose: To perform a comprehensive bibliometric analysis to evaluate the 100 top-cited articles on the MPFL. Study Design: Cross-sectional study. Methods: We searched the Scopus database in December 2022 using the terms "medial patellofemoral ligament" OR "MPFL." The search was confined to English-language articles, including technical notes, systematic reviews on clinical outcomes and/or complications, clinical studies, studies regarding complications, and basic science articles (either cadaveric or biomechanical); we excluded letters, case reports, personal opinions, guidelines, editorials, and narrative or other types of reviews. Analysis of the 100 top-cited articles was performed according to total number of citations, average citations per year (ACY), study type, country of origin, journal of publication, affiliated institution, and most published authors. Results: The total number of citations was 16,358 (range of citations per article, 72-692). The majority of articles were published as clinical studies (54%), with cadaveric studies being the second most common (21%). Most studies originated in the United States (32%), with Japan (15%) and Germany (13%) following. The American Journal of Sports Medicine published the majority of the 100 top-cited articles (37/100; 6304 citations) as well as the 10 top-cited articles according to ACY (7/10; mean, 285.14 citations). The most prolific authors were Nomura (8 articles); Burks (6 articles); and Inoue, Sillanpää, and Dreyhaupt (5 articles each). Conclusion: By analyzing the characteristics of the 100 top-cited articles, this study demonstrated that the MPFL is a growing and popular area of research, with the focus varying through timeline trends. Questions regarding MPFL anatomy, isometry, and biomechanics might have been answered adequately, but research regarding optimal fixation technique under various circumstances is still ongoing.

MPFL Reconstruction and Implant-Mediated Guided Growth in Skeletally Immature Patients With Patellar Instability and Genu Valgum.

BACKGROUND: There is a higher rate of failure of isolated MPFL reconstruction in skeletally immature patients with patellar instability compared to skeletally mature patients. Genu valgum is a known risk factor for patellar instability. There is potential for concomitant surgical correction of genu valgum to achieve better clinical outcomes and to decrease failure rates of MPFL reconstruction. PURPOSE: To evaluate outcomes of combined medial patellofemoral ligament (MPFL) reconstruction and implant-mediated guided growth (IMGG) in skeletally immature patients with patellar instability and genu valgum. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: In a multicenter study, all skeletally immature patients with recurrent patellar instability and genu valgum who underwent MPFL reconstruction using hamstring graft and IMGG using a transphyseal screw or tension band plate for the distal femur and/or proximal tibia were included. The knee valgus angle and mechanical axis were measured on full-length radiographs and anatomic risk factors were measured on MRI. Patients were followed until correction of their lower limb alignment and implant removal or until skeletal maturity. Clinical outcomes, including complications, were analyzed. RESULTS: A total of 31 patients (37 knees) were included in the study. The mean age and skeletal age of the cohort were 12.4 and 12.9 years, respectively. Simultaneous MPFL reconstruction and IMGG were performed in 26 of 37 knees; 11 underwent staged procedures. Twenty knees had transphyseal screws and 17 knees had tension band plates for IMGG. The knee valgus corrected from a mean of 12.4° to 5.1° in 12.1 months. Implants were removed from 22 of 37 knees once genu valgum was corrected. There was no significant difference (P = .65) in the correction rate between plates (0.7 deg/month) and screws (0.6 deg/month). Ten complications occurred in 4 patients (7 knees) and included 5 patellar redislocations, 2 rebound valgus, 1 varus overcorrection, 1 knee arthrofibrosis, and 1 implant loosening. For children <10 years of age, 3 of 6 (50%) knees had patellar redislocations and 5 of 6 knees had a complication. This was statistically significant (P = .003) compared with patients >10 years of age. Similarly, for patients with bilateral knee involvement, 5 of 12 (42%) knees had patellar redislocations and a total of 8 complications occurred in this subset. This was statistically significant (P < .001) compared with patients with unilateral involvement. CONCLUSION: IMGG with plates or screws in the setting of combined MPFL reconstruction improves genu valgum. Children <10 years of age and those with bilateral instability with genu valgum remain difficult subsets to treat with higher complication rates.